hey John, just got back online to check for your reply. I would certainly be interested in contacting you in some way, be it over the phone or text (doesn't matter either way to me). unfortunately I am out of town for the weekend and away from my mustang (probably for the better, lol) I will be back at home and wrenching again Sunday afternoon. I would certainly like to get in touch then and see if we could get this problem worked out (have now been battling it for a good 6 weeks or better). my number is 605-690-9722, feel free to shoot me a text if you have any questions about my car. again, can't thank you enough for all the help. I really do appreciate someone taking the time to explain what could possibly be going on and why it would be occurring.
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08GT500
5 Year Member
That sounds great! I’ll give you a buzz, text first- once you’re back,!id caught 11 Large Mouth Bass “Weeee’re eatin’ Toniiite’! lol! Think on this- The basics hopefully yield something, the items need be addressed (Vapor Canister)Mass Airflow Sensor being dirty, and my #2 would be the PIP in the Distributor. Basics first- know they’re solid- then- right? I’m giving you a lot of information, Bro., for reference if needed and how it all intertwines- but read it like a Map- start simple-zoom into the area you want first- the basics, cleaning and integrity of connections and grounds, vacuum line issues, plugs cleaned and gapped correctly, Air Filter, MAF, dump the CPU Codes (still present issue will come back quick to your EEC, or may not let you Dump the Codes in the first place until corrected).
Fire it at night and look for secondary Coil Arc’s between Wires, or Coil cracks. Have fun- I’ll talk to you Sunday!! Be safe! J
Fire it at night and look for secondary Coil Arc’s between Wires, or Coil cracks. Have fun- I’ll talk to you Sunday!! Be safe! J
Have you changed the fuel filter?
What are the engine running codes? Run the cylinder balance test and accomplish 2 things at once.
Cylinder balance test: use this to find dead or weak cylinders:
Revised 09-Sep-2017 Added reminder to write down the stored codes and engine running codes.
The computer has a cylinder balance test that helps locate cylinders with low power output. You’ll need to dump the codes out of the computer and make sure that you have the A/C off, clutch depressed to the floor and the transmission in neutral. Fail to do this and you can’t do the engine running dump codes test that allows you to do the cylinder balance test.
Here's the way to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great. You watch the flashing test lamp or Check Engine Light and count the flashes.
Be sure to turn off the A/C, have the clutch depressed to the floor, and put the transmission in neutral when dumping the codes. Fail to do this and you will generate a code 67 and not be able to dump the Engine Running codes.
Here's how to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great. You watch the flashing test lamp or Check Engine Light and count the flashes.
If your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.
The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.
89 through 95 cars have a working Check Engine light. Watch it instead of using a test lamp.
The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.
WARNING!!! There is a single dark brown connector with a black/orange wire. It is the 12 volt power to the under the hood light. Do not jumper it to the computer test connector. If you do, you will damage the computer.
What to expect:
You should get a code 11 (two single flashes in succession). This says that the computer's internal workings are OK, and that the wiring to put the computer into diagnostic mode is good. No code 11 and you have some wiring problems.
This is crucial: the same wire that provides the ground to dump the codes provides signal ground for the TPS, EGR, ACT and Map/Baro sensors. If it fails, you will have poor performance, economy and drivability problems
Some codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.
Dumping the Engine Running codes: The procedure is the same, you dump the codes and then you start the engine with the test jumper in place. Be sure the A/C is off, clutch depressed to the floor and the transmission is in neutral. You'll get an 11, then a 4 and the engine will speed up to do the EGR test. After the engine speed decreases back to idle, it will dump the engine running codes.
Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.
Your 86-88 5.0 won't have a working Check Engine Light, so you'll need a test light.
See AutoZone Part Number: 25886 , $10
Alternate methods:
For those who are intimidated by all the wires & connections, see Actron® for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Wal-Mart.
Or for a nicer scanner see www.midwayautosupply.com/Equus-Digital-Ford-Code-Reader/dp/B000EW0KHW Equus - Digital Ford Code Reader 3145.
It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $22-$36.
Order it at Walmart for a better price and free shipping
Write down the codes that the computer outputs since they will give you information on problems that are stored in the computer's memory
Cylinder balance test
If you have idle or IAC/IAB problems and the engine will not idle on its own without mechanically adjusting the base idle speed above 625-750 RPM, this test will fail with random cylinders pointed out every time it runs. The IAC/IAB must be capable of controlling the engine speed to run in the 1300-1500 RPM range. Playing with the base idle speed by adjusting it upwards will not work, the computer has to be able to control the engine speed using the IAC/IAB.
Warm the car's engine up to normal operating temperature. With the test jumper in test position, start the engine and let it stabilize. It should flash a 10 and then a 4 and maybe an 11. If no 11, then there are other codes that will be dumped.
Write down the codes that the computer outputs since they will give you information that the computer found when it is running. These are often different from the stored codes.
One of the first tests it does is to open the EGR all the way, this will cause the engine to stumble and almost die. If the engine dies here then you have EGR problems.
To start the cylinder balance test, briefly floor the accelerator past 2500 RPM and let off the accelerator. The engine will stabilize at about 1300-1450 RPM and the cut off the fuel injectors one at a time. The engine speed will drop briefly and the computer will turn the fuel injector for the cylinder under test back on. Then it starts the process for the next cylinder. When it has sequenced through all 8 injectors, it will flash 9 for everything OK, or the number of the failing cylinder such as 2 for cylinder #2. Quickly pressing the throttle again up to 2500 RPM’s will cause the test to re-run with smaller qualifying figures.
Do it a third time, and if the same cylinder shows up, the cylinder is weak and isn’t putting out power like it should. See the Chilton’s Shop manual for the complete test procedure
See
View: https://www.youtube.com/watch?v=HDXrkKS4jTE
for a visual tour through the process. There is no voice narration so you have to listen carefully for the engine sounds. I posted the link for the benefit of Stangnet members who had questions about how to do a cylinder balance test. I do not own that video and I am not the creator.
Do a compression test on all the cylinders.
Take special note of any cylinder that shows up as weak in the cylinder balance test. Low compression on one of these cylinders rules out the injectors as being the most likely cause of the problem. Look at cylinders that fail the cylinder balance test but have good compression. These cylinders either have a bad injector, bad spark plug or spark plug wire. Move the wire and then the spark plug to another cylinder and run the cylinder balance test again. If it follows the moved wire or spark plug, you have found the problem. If the same cylinder fails the test again, the injector is bad. If different cylinders fail the cylinder balance test, you have ignition problems or wiring problems in the 10 pin black & white electrical connectors located by the EGR.
How to do a compression test:
Only use a compression tester with a screw in adapter for the spark plug hole. The other type leaks too much to get an accurate reading. Your local auto parts store may have a compression tester to rent/loan. If you do mechanic work on your own car on a regular basis, it would be a good tool to add to your collection.
With the engine warmed up, remove all spark plugs and prop the throttle wide open with a plastic screwdriver handle between the throttle butterfly and the throttle housing. Crank the engine until it the gage reading stops increasing. On a cold engine, it will be hard to tell what's good & what's not. Some of the recent posts have numbers ranging from 140-170 PSI. If the compression is low, squirt some oil in the cylinder and do it again – if it comes up, the rings are worn. There should be no more than 10% difference between cylinders. Use a blow down leak test (puts compressed air inside cylinders) on cylinders that have more than 10% difference.
I generally use a big screwdriver handle stuck in the TB between the butterfly and the TB to prop the throttle open. The plastic is soft enough that it won't damage anything and won't get sucked down the intake either.
A battery charger (not the trickle type) is a good thing to have if you haven't driven the car lately or if you have any doubts about the battery's health. Connect it up while you are cranking the engine and it will help keep the starter cranking at a consistent speed from the first cylinder tested to the last cylinder.
What are the engine running codes? Run the cylinder balance test and accomplish 2 things at once.
Cylinder balance test: use this to find dead or weak cylinders:
Revised 09-Sep-2017 Added reminder to write down the stored codes and engine running codes.
The computer has a cylinder balance test that helps locate cylinders with low power output. You’ll need to dump the codes out of the computer and make sure that you have the A/C off, clutch depressed to the floor and the transmission in neutral. Fail to do this and you can’t do the engine running dump codes test that allows you to do the cylinder balance test.
Here's the way to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great. You watch the flashing test lamp or Check Engine Light and count the flashes.
Be sure to turn off the A/C, have the clutch depressed to the floor, and put the transmission in neutral when dumping the codes. Fail to do this and you will generate a code 67 and not be able to dump the Engine Running codes.
Here's how to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great. You watch the flashing test lamp or Check Engine Light and count the flashes.
If your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.
The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.
89 through 95 cars have a working Check Engine light. Watch it instead of using a test lamp.
The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.
WARNING!!! There is a single dark brown connector with a black/orange wire. It is the 12 volt power to the under the hood light. Do not jumper it to the computer test connector. If you do, you will damage the computer.
What to expect:
You should get a code 11 (two single flashes in succession). This says that the computer's internal workings are OK, and that the wiring to put the computer into diagnostic mode is good. No code 11 and you have some wiring problems.
This is crucial: the same wire that provides the ground to dump the codes provides signal ground for the TPS, EGR, ACT and Map/Baro sensors. If it fails, you will have poor performance, economy and drivability problems
Some codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.
Dumping the Engine Running codes: The procedure is the same, you dump the codes and then you start the engine with the test jumper in place. Be sure the A/C is off, clutch depressed to the floor and the transmission is in neutral. You'll get an 11, then a 4 and the engine will speed up to do the EGR test. After the engine speed decreases back to idle, it will dump the engine running codes.
Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.
Your 86-88 5.0 won't have a working Check Engine Light, so you'll need a test light.
See AutoZone Part Number: 25886 , $10
Alternate methods:
For those who are intimidated by all the wires & connections, see Actron® for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Wal-Mart.
Or for a nicer scanner see www.midwayautosupply.com/Equus-Digital-Ford-Code-Reader/dp/B000EW0KHW Equus - Digital Ford Code Reader 3145.
It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $22-$36.
Order it at Walmart for a better price and free shipping
Write down the codes that the computer outputs since they will give you information on problems that are stored in the computer's memory
Cylinder balance test
If you have idle or IAC/IAB problems and the engine will not idle on its own without mechanically adjusting the base idle speed above 625-750 RPM, this test will fail with random cylinders pointed out every time it runs. The IAC/IAB must be capable of controlling the engine speed to run in the 1300-1500 RPM range. Playing with the base idle speed by adjusting it upwards will not work, the computer has to be able to control the engine speed using the IAC/IAB.
Warm the car's engine up to normal operating temperature. With the test jumper in test position, start the engine and let it stabilize. It should flash a 10 and then a 4 and maybe an 11. If no 11, then there are other codes that will be dumped.
Write down the codes that the computer outputs since they will give you information that the computer found when it is running. These are often different from the stored codes.
One of the first tests it does is to open the EGR all the way, this will cause the engine to stumble and almost die. If the engine dies here then you have EGR problems.
To start the cylinder balance test, briefly floor the accelerator past 2500 RPM and let off the accelerator. The engine will stabilize at about 1300-1450 RPM and the cut off the fuel injectors one at a time. The engine speed will drop briefly and the computer will turn the fuel injector for the cylinder under test back on. Then it starts the process for the next cylinder. When it has sequenced through all 8 injectors, it will flash 9 for everything OK, or the number of the failing cylinder such as 2 for cylinder #2. Quickly pressing the throttle again up to 2500 RPM’s will cause the test to re-run with smaller qualifying figures.
Do it a third time, and if the same cylinder shows up, the cylinder is weak and isn’t putting out power like it should. See the Chilton’s Shop manual for the complete test procedure
See
View: https://www.youtube.com/watch?v=HDXrkKS4jTE
for a visual tour through the process. There is no voice narration so you have to listen carefully for the engine sounds. I posted the link for the benefit of Stangnet members who had questions about how to do a cylinder balance test. I do not own that video and I am not the creator.
Do a compression test on all the cylinders.
Take special note of any cylinder that shows up as weak in the cylinder balance test. Low compression on one of these cylinders rules out the injectors as being the most likely cause of the problem. Look at cylinders that fail the cylinder balance test but have good compression. These cylinders either have a bad injector, bad spark plug or spark plug wire. Move the wire and then the spark plug to another cylinder and run the cylinder balance test again. If it follows the moved wire or spark plug, you have found the problem. If the same cylinder fails the test again, the injector is bad. If different cylinders fail the cylinder balance test, you have ignition problems or wiring problems in the 10 pin black & white electrical connectors located by the EGR.
How to do a compression test:
Only use a compression tester with a screw in adapter for the spark plug hole. The other type leaks too much to get an accurate reading. Your local auto parts store may have a compression tester to rent/loan. If you do mechanic work on your own car on a regular basis, it would be a good tool to add to your collection.
With the engine warmed up, remove all spark plugs and prop the throttle wide open with a plastic screwdriver handle between the throttle butterfly and the throttle housing. Crank the engine until it the gage reading stops increasing. On a cold engine, it will be hard to tell what's good & what's not. Some of the recent posts have numbers ranging from 140-170 PSI. If the compression is low, squirt some oil in the cylinder and do it again – if it comes up, the rings are worn. There should be no more than 10% difference between cylinders. Use a blow down leak test (puts compressed air inside cylinders) on cylinders that have more than 10% difference.
I generally use a big screwdriver handle stuck in the TB between the butterfly and the TB to prop the throttle open. The plastic is soft enough that it won't damage anything and won't get sucked down the intake either.
A battery charger (not the trickle type) is a good thing to have if you haven't driven the car lately or if you have any doubts about the battery's health. Connect it up while you are cranking the engine and it will help keep the starter cranking at a consistent speed from the first cylinder tested to the last cylinder.
08GT500
5 Year Member
Just a few Notes- Dissertation. I thought I you had said that you tried more than one Tif Sensor, I’ve seen 3 in a row bad right off the shelf.. Get a Second, check out Rock Auto Parts online. Good Parts, Prices- Guarantees honored. Chain Auto stores are really a joke, use in a bind - they’re trained to sway you to go aftermarket, tell them to go to hell- buy Ford OEM Parts. The only other use is... that answer is STEEPER in near impossibility than climbing Everest with COPD - lemme think on that a bit one.I’ll talk to you on Sunday, work through the Sensors & CPU troubleshooting. You’d used plenty of Heat Sink compound when you’d installed the last Tif- and it was Genuine OEM- Yes? Dizzy Casting is the Heat Sink for the tif, Thermal transfer to it from the Tif is imperative, as is solid Dizzy electrical Grounding.. I’d spoke of seeing if the high RPM miss exists on the Motor not yet at operating Temperature, now that the Fuel is a’ flowin’, if this Car did not have issue before Build- you have a few Parts, likely to safely Sub-in. Not just yet, though. (fired up- run for a minute or two- having clean Plugs- ripping through 1st gear to 2nd WOT to 6K. (Safe spot). The Cheap Mfg’s that HAD good Parts, are now running on Name only. In the 1970’s when Reggie Jackson was promoting- AccEL Products, they COMPETED/STRIVED for Quality. Lots of trash, now. Aftermarket Sensors are and many Plug types-not all, are a waste of Money. At this performance level- go OEM. I run an MSD Crank Trigger, was a 1,500$ System- never failed me (yet). 5 Years- Runs superb. Different levels of Build- Necessity, bigger expense. You’d previously Tried an alternate Distributor (which made things worse) it obviously had problems of it’s own. IT MAY still have a viable Part or 2 you can use, Temporarily(Module) however. I don’t throw away most of my Parts- so I have things on hand I or another may need, i’ve some Fox stuff- Check on that.... As your problem was, in actuality, more than just a High RPM miss, and some Bolt-one on a Built Motor that need to be addresed. The simple path- System integrity check of Basics to correct any other areas where repairs were made by someone else, already in the Car waiting to initiate doom at the worst possible time, and test that Parts replaced/repairs made are sound.
Your choices are- #1) Check BASICS now, gain more info.while doing so- repair blatantly obvious anomalies. Have a great time in your Car that’s now reliable, drive anywhere with zero thought of unknowns wreaking havoc. There’s ALWAYS a chance of problems, that old expression has Truth “if it has Ti*’s or Gears, you will have problems with it” lol! (Text Can be adjusted for/by the Female readers-no pun intended) but reliability issues should be the LAST thing on your mind, correcting the obvious is the point- and will likely correct/at minimal Identify the remaining, thought Originally to be the only- issue. #2) .... Not KNOWING if Vehicle reliability is there to stay and just nail the “miss” issue.
Useful thing I’ve learned about spending a day verifying/correcting BASICS. It seems there are a few likely still needing that attention based on the issues that arose the last Week alone. Surely do not want to stack issues, . You put a lot of $$ into this- to enjoy it, Drive it anywhere with no concerns of anything, as You meticulously verified it as correct. Learned in the process. Bill for services rendered by Passing it forward. Post up your experience, the items found, what you did & why. Too Many obsess over one issue, yet see anomalies they could repair in 5 Minutes. But don’t. I’ve done it- who hasn’t? It’s Tunnel vision- got to get it running now, i’ll Get to the other issue- later, and yet have the audacity to wonder why it bites them in the Arse later when it does occur.
Ignition Switch was bad and fell apart- replaced. Tif failed, Fuel System was intermittently supplying Pressury while Driving due to a severely corroded connector. Many intermittent problems are resolved. Now you’re closer to having the only issue thought present (the miss @ 4K + @ 100% pedal). (It’s Ironic before you wanted the High RPM Miss gone, now- you’re hoping just for ONLY it- to fix) You’ve now a Codereader, and a Digital Multimeter, you’re troubleshooting, learned a lot in a Week. Ya think?
Codes sent are a few things that need be dealt with, is one ECU Ground/backup and relearn (Likely from disconnecting Battery to repair Fuel issue). Running list of a Few more questions on the BAMA info and previous conditions prior to
the 306 transplant. Running Condition, Exhaust, Cats.Headers, H or X-Pipe?Sounds like the Break-in was Textbook, If you were on a Lift with the Car, or just jack/Stands on “that” Day?
Sunday conversation.
TWO of the biggest Misconceptions, (Not you-in General) is that if you replace something with a new Part- “it can now be ruled out- as it’s NEW, it now functions correctly” (Wish that were true, don’t think I’m alone with this thought, not by a long shot) but physically verifying/testing the outcome by Parameter measurement - not how a given Vehicle runs, is perhaps the most important step). The other one is: Aftermarket ignition Parts & Plugs being superior to OEM Parts. At these “Stock level replacement” Parts of type, this could not be more incorrect. OEM Ford Sensors are superior and MUCH better in overall terms of reliability. Motorcraft Plugs are excellent- OEM Performance Ford Plug Wires are excellent as well.
These MSD, ACCEL Parts are Excellent in ONE Capacity-if you already HAVE them installed... its usually the direction from which need look to first and from which your poor Performance or non-Operation Issue is derived.lol!
Pull the Plugs and inspect condition, note the electrode Color& how to ‘read them’- regap.to spec’s. Replace Plugs if ANY doubt exists regarding them, temperate (White Color, Specifically electrode Insulator cracking, radiused ground) and Never-Seize on these Threads is a Natural. Clean/ Use NDielectric grease on every Plug/Cap connection. ‘NoAlox’ Anti-Corrosive On correctly prepared Bare surfaces for Ring Stud Chassis, Component, Block Grounds. Lasts, repels H20, AL/CU usage (Copper or Aluminum) so you know it’s a High Resistance connection, stays that way.
As it was a confirmed the intermittent lean condition existed at high rpm’s, it’s highly fortunate Cylinder Temp’s didn’t go Crispy-melt a Piston, Valve margin Grind, a Plug disintegration, tear up the Bore@ those RPM’s.... Once the basic items are complete- I.e. Plugs, Wires, Cap, Rotor, your Air Filter replaced/Cleaned our, Fuel Volume Check, V-ref., Disconnected MAF- engine response, Timing pull back to 12 Deg. SPOUT, Octane, Idle setting, Fuel vapors present, Vacuum line(s) integrity- Electrical’s Connected/Terminated securely, verify no Wires from 02’s burnt to the exhaust, irony of issues once lifted, removing/Cleaning out the MAF using CRC MAF CLEANER- good in your Dizzy, too. Spray solvents May contain “isocyanates” ( a nasty Carcinogen used initially in 80’s Genre’ higher end Enamels like Dupont’s Centari/2000S and Imron.-ended up as a potentiator in Aresol Solvents/ Cleaners. It’s known to cause severe Neurological defects and Cancer upon limited exposure, BIG issue- Mfg’s are NOT even required to list it on certain Container’s nomenclature.
After doing the Basics, of course you use the OBD-1 Diagnostics as the “EEK”s waiting to give you it’s info,. Implementing it’s Testing abilities, document, repair, Dump Codes....And a Partridge in a Pear Tree....
i’ll emulate your BAMA Tune once it’s time, if needed, I can Datalog and ascertain much more feedback info- not like an OBD-2, but much improved. Can run through the Tests, btw your TPS Voltage across the is ok as measured. As TPS is a potentiometer- variable Resistor- they can have areas where they can unevenly wear (like a cheap/Old Stereo Speaker crackling as you turn up/down Volume) producing an inconsistent output..Cleaning can help, again-CRC. Simple Test, like the rest. Know what the Rev issue is- other info I’ll discuss for the CAI setup, anyhoo- Put the 89 back together- screams.Done at 8:30AM. 370$ Ticket at 10AM P.S. I Don’t think your LX likes that Bay96’ GT Timing Chain jump- He.Wants NOS, Non P.I. 4.6l[/QUOTE]
Your choices are- #1) Check BASICS now, gain more info.while doing so- repair blatantly obvious anomalies. Have a great time in your Car that’s now reliable, drive anywhere with zero thought of unknowns wreaking havoc. There’s ALWAYS a chance of problems, that old expression has Truth “if it has Ti*’s or Gears, you will have problems with it” lol! (Text Can be adjusted for/by the Female readers-no pun intended) but reliability issues should be the LAST thing on your mind, correcting the obvious is the point- and will likely correct/at minimal Identify the remaining, thought Originally to be the only- issue. #2) .... Not KNOWING if Vehicle reliability is there to stay and just nail the “miss” issue.
Useful thing I’ve learned about spending a day verifying/correcting BASICS. It seems there are a few likely still needing that attention based on the issues that arose the last Week alone. Surely do not want to stack issues, . You put a lot of $$ into this- to enjoy it, Drive it anywhere with no concerns of anything, as You meticulously verified it as correct. Learned in the process. Bill for services rendered by Passing it forward. Post up your experience, the items found, what you did & why. Too Many obsess over one issue, yet see anomalies they could repair in 5 Minutes. But don’t. I’ve done it- who hasn’t? It’s Tunnel vision- got to get it running now, i’ll Get to the other issue- later, and yet have the audacity to wonder why it bites them in the Arse later when it does occur.
Ignition Switch was bad and fell apart- replaced. Tif failed, Fuel System was intermittently supplying Pressury while Driving due to a severely corroded connector. Many intermittent problems are resolved. Now you’re closer to having the only issue thought present (the miss @ 4K + @ 100% pedal). (It’s Ironic before you wanted the High RPM Miss gone, now- you’re hoping just for ONLY it- to fix) You’ve now a Codereader, and a Digital Multimeter, you’re troubleshooting, learned a lot in a Week. Ya think?
Codes sent are a few things that need be dealt with, is one ECU Ground/backup and relearn (Likely from disconnecting Battery to repair Fuel issue). Running list of a Few more questions on the BAMA info and previous conditions prior to
the 306 transplant. Running Condition, Exhaust, Cats.Headers, H or X-Pipe?Sounds like the Break-in was Textbook, If you were on a Lift with the Car, or just jack/Stands on “that” Day?
Sunday conversation.
TWO of the biggest Misconceptions, (Not you-in General) is that if you replace something with a new Part- “it can now be ruled out- as it’s NEW, it now functions correctly” (Wish that were true, don’t think I’m alone with this thought, not by a long shot) but physically verifying/testing the outcome by Parameter measurement - not how a given Vehicle runs, is perhaps the most important step). The other one is: Aftermarket ignition Parts & Plugs being superior to OEM Parts. At these “Stock level replacement” Parts of type, this could not be more incorrect. OEM Ford Sensors are superior and MUCH better in overall terms of reliability. Motorcraft Plugs are excellent- OEM Performance Ford Plug Wires are excellent as well.
These MSD, ACCEL Parts are Excellent in ONE Capacity-if you already HAVE them installed... its usually the direction from which need look to first and from which your poor Performance or non-Operation Issue is derived.lol!
Pull the Plugs and inspect condition, note the electrode Color& how to ‘read them’- regap.to spec’s. Replace Plugs if ANY doubt exists regarding them, temperate (White Color, Specifically electrode Insulator cracking, radiused ground) and Never-Seize on these Threads is a Natural. Clean/ Use NDielectric grease on every Plug/Cap connection. ‘NoAlox’ Anti-Corrosive On correctly prepared Bare surfaces for Ring Stud Chassis, Component, Block Grounds. Lasts, repels H20, AL/CU usage (Copper or Aluminum) so you know it’s a High Resistance connection, stays that way.
As it was a confirmed the intermittent lean condition existed at high rpm’s, it’s highly fortunate Cylinder Temp’s didn’t go Crispy-melt a Piston, Valve margin Grind, a Plug disintegration, tear up the Bore@ those RPM’s.... Once the basic items are complete- I.e. Plugs, Wires, Cap, Rotor, your Air Filter replaced/Cleaned our, Fuel Volume Check, V-ref., Disconnected MAF- engine response, Timing pull back to 12 Deg. SPOUT, Octane, Idle setting, Fuel vapors present, Vacuum line(s) integrity- Electrical’s Connected/Terminated securely, verify no Wires from 02’s burnt to the exhaust, irony of issues once lifted, removing/Cleaning out the MAF using CRC MAF CLEANER- good in your Dizzy, too. Spray solvents May contain “isocyanates” ( a nasty Carcinogen used initially in 80’s Genre’ higher end Enamels like Dupont’s Centari/2000S and Imron.-ended up as a potentiator in Aresol Solvents/ Cleaners. It’s known to cause severe Neurological defects and Cancer upon limited exposure, BIG issue- Mfg’s are NOT even required to list it on certain Container’s nomenclature.
After doing the Basics, of course you use the OBD-1 Diagnostics as the “EEK”s waiting to give you it’s info,. Implementing it’s Testing abilities, document, repair, Dump Codes....And a Partridge in a Pear Tree....
i’ll emulate your BAMA Tune once it’s time, if needed, I can Datalog and ascertain much more feedback info- not like an OBD-2, but much improved. Can run through the Tests, btw your TPS Voltage across the is ok as measured. As TPS is a potentiometer- variable Resistor- they can have areas where they can unevenly wear (like a cheap/Old Stereo Speaker crackling as you turn up/down Volume) producing an inconsistent output..Cleaning can help, again-CRC. Simple Test, like the rest. Know what the Rev issue is- other info I’ll discuss for the CAI setup, anyhoo- Put the 89 back together- screams.Done at 8:30AM. 370$ Ticket at 10AM P.S. I Don’t think your LX likes that Bay96’ GT Timing Chain jump- He.Wants NOS, Non P.I. 4.6l[/QUOTE]
@gstsaver
I'm fixing to dump a lot of very technical stuff on your plate, so you may want to print it out and highlight the sections that relate to your current problem.
Fuel injectors inoperative, one or more injectors either on all the time or will not squirt.
Revised 11 Aug 2018 to clarify injector wiring continuity testing
Tools needed: Noid light, Multimeter (volts & ohms), 10 MM socket &
extension, & ratchet.
Note: Do all of the steps and do them in order. The results of the subsequent tests are based on the prior tests being successfully passed.
1.) Each injector has a red power wire to provide power to the injector. Turn the ignition switch to Run and remove each injector electrical connector and use the multimeter to check for 12 volts on the red wire. Each injector should have 12 volts +/- .5 volt. More voltage is always better than less voltage. No 12 volts on a singe injector and the wiring for that injector is broken inside the engine fuel injector harness.
No 12 volts on all injectors:
A.) Check for a bad connection at the 10 pin connector. Check for 12 volts at red wire on the MAF or TAD/TAB solenoids mounted on the aft side of the passenger strut tower. Good 12 volts there and you have a wiring problem with the 10 pin connectors or associated wiring.
See the graphic for the location of the 10 pin connectors:
See the graphic for the 10 pin connector circuit layout.
The injector power pin is the VPWR pin in the black 10 pin connector. [/b]
B.) Bad ECC power relay. The relay is on top of the computer, it provides power to the fuel injector system. This is relevant ONLY if you do not have power to all injectors.
It is somewhat difficult to get to, since it requires you to remove the computer from its 2 bolt mounting.. If the relay or socket is bad, you will not have 12 volts on any of the red wires in the engine compartment or to pins 37/57 on the computer. The pins 37/57 are the main power feed to the computer.
C.) Blown fuse link – The blue fuse link for the computer is up near the starter solenoid. Check for no 12 volts on the ECC relay socket or computer black/orange wires. No 12 volts and the fuse link is blown open. If the fuse link blows, there is no power for any of the computer functions.
D.) Bad wiring. Broken or damaged red wire to the chassis side of the 10 pin connectors.
Some basics about the computer:
Remember that the computer does not supply power for any actuator or relay. It provides the ground necessary to complete the circuit. That means one side of the circuit will always be hot, and the other side will go to ground or below 1 volt as the computer switches on that circuit.
2.) Get a noid light from AutoZone or other auto parts store, or even better a set of them.
This one is from http://www.summitracing.com/parts/oes-25142?seid=srese1&gclid=CMXk7M6dmM0CFdgOgQodGUMHWQ and costs about $6.
3.) Use the noid light to determine that the injector pulses and isn’t stuck in the on position.
It you have a set of them install all of them and compare the pulse intensity. Install the noid lights, turn the ignition switch to Run and crank the engine. A light that doesn’t pulse and stays on has a short to ground in the computer side of the circuit. That can be either a wiring fault or a failed computer.
If this is the case, remove the passenger side lick panel and disconnect the computer connector.
There is one 10 MM bolt holding it in place. Pull the connector all the way out of the computer so that you can see the computer side pins.
Disconnect all 8 fuel injector connectors from the injectors and leave them disconnected for steps 4-6.
Use the list from the graphic below to find the fuel injector pins for the injectors that didn’t turn the noid light off.
4.) Set the multimeter to low scale Ohms and measure between the computer ground located below the computer and the suspect fuel injector pins. You should see greater than 100 K Ohms resistance. If you see less than 100K Ohms, the wiring between the injector and the computer has an internal short to ground and needs service.
Check the harness and look for damage, kinks or frayed spots. A short to ground would result in an injector that never turned off.
5.) A single noid light that never turns on is either a wiring fault, or a failed computer. Either the injector has no DC power or the computer or wiring has failed and cannot switch the injector circuit to ground. Determine if the injector has power by using the multimeter to check for 12 volts on the red wire on the suspect injector connector. No 12 volts and you have a wiring fault.
If none of the noid lights flash and you have 12 volts at each injector, check to see that you have good spark. Before you even think about replacing the computer, see step 6.
Check the injector wiring for open circuit or broken wiring or bad connections.
Check the harness and look for damage, kinks or frayed spots. Check the 10 pin salt & pepper shaker connectors for bent pins, corrosion and damage.
Next check the fuel injector wiring for open circuits. Set the multimeter to low scale Ohms. Each fuel injector has a red wire (power) and a non-red wire (computer controlled ground).
Inside the car, take a short piece of 14 gauge bare wire and jumper it to the ground below the computer. Use the computer wiring diagram and select one of the injectors. The recommended procedure is to start with cylinder #1 and test each injector in numerical sequence 1,2,3, etc. Then stick the ground wire into the computer wiring harness socket for the injector you want to test. Don’t forget to move the ground inside the car each time you test a different injector.
Under the hood, set the multimeter to low ohms and ground one of the test leads to the engine block. Then measure the resistance between the non-red fuel injector wire in the fuel injector connector and the meter ground on the engine block. You should see less than 1 Ohm. More than that means a bad connection or bad wiring.
The 10 pin connectors are the first place to look for problems when it fails the above test.
Engine side testing Unplug the black 10 pin connector from its' mating half. Use the 10 pin connector diagram in this tech note to locate the injector you are currently testing. Measure the resistance between the non-red injector wire and the injector pin on the engine mounted side of the fuel injector harness; you should see 1 Ohm or less. More than that indicates a broken wire or bad connection.
Body side testing Use the 10 pin connector diagram in this tech note to locate the injector you are currently testing. Again, the black connector that is connected to the car body side of the wiring harness is the one to use for this test. Make sure that you test the injector pin for the wire side of the computer wiring harness pin that you grounded. Ground one lead of the multimeter on the engine block and check the resistance; you should see 1 Ohm or less. Test all 8 injectors in numerical sequence, and move the grounding wire at the computer wiring harness inside the car each time you test a different injector.
6.) Use an ohmmeter set on the low resistance scale and measure the resistance of each injector across the two contacts inside the injector electrical connector. You should see between 11-16 ohms. More or less than that is a bad injector. Next, measure between either one of the contacts and the metal on the injector body. You should see greater than 100,000 ohms. Don’t hold the metal probe tips with your bare hands when you make this measurement; It will give incorrect results if you do.
Once you have determined that the suspect injectors have good power and good wiring, the computer is the likely suspect, since a ground is required to complete a circuit and make it function. The computer provides the ground: if doesn’t, then the noid light will not flash. If the noid light stays on, the computer has an internal failure.
7) If you have gotten this far, then the problem is likely ignition related. Remember the noid test using all of the noid lights? All of them were supposed to be equally bright. Since you have already tested all the electrical side of the fuel injector circuit, the one remaining common item is the pip sensor inside the distributor. A failing pip sensor, damaged shutter wheel or bent distributor shaft could all cause the pulse delivered to the injectors to be faulty. A bad pip sensor will cause all the injectors not to fire and you will have no spark. Dumping the codes will usually show a code 14.
8) Spark plugs indicate one or more cylinders not firing: use the multimeter to measure the resistance of the spark plug wires. The wires should measure 2000 ohms per foot of length. A 2 foot wire would be 4000 ohms and a 3 foot wire would be 6000 ohms. Some Taylor and Accel wires have metal cores and will measure much less: that’s OK.
Next examine the spark plug wires very carefully for burn spots, cracks and damaged insulation. One good thing to try is to start the engine while the car is a very dark area, open the hood and look for sparks or blue glow. They indicate the electricity is leaking out of the spark plug wires.
Thanks to Tmoss & Stang&2birds at www.veryuseful.com/mustang/tech/engine/ for some of the graphics
Thanks also to www.oldfuelinjection.com for some of the graphics.
I'm fixing to dump a lot of very technical stuff on your plate, so you may want to print it out and highlight the sections that relate to your current problem.
Fuel injectors inoperative, one or more injectors either on all the time or will not squirt.
Revised 11 Aug 2018 to clarify injector wiring continuity testing
Tools needed: Noid light, Multimeter (volts & ohms), 10 MM socket &
extension, & ratchet.
Note: Do all of the steps and do them in order. The results of the subsequent tests are based on the prior tests being successfully passed.
1.) Each injector has a red power wire to provide power to the injector. Turn the ignition switch to Run and remove each injector electrical connector and use the multimeter to check for 12 volts on the red wire. Each injector should have 12 volts +/- .5 volt. More voltage is always better than less voltage. No 12 volts on a singe injector and the wiring for that injector is broken inside the engine fuel injector harness.
No 12 volts on all injectors:
A.) Check for a bad connection at the 10 pin connector. Check for 12 volts at red wire on the MAF or TAD/TAB solenoids mounted on the aft side of the passenger strut tower. Good 12 volts there and you have a wiring problem with the 10 pin connectors or associated wiring.
See the graphic for the location of the 10 pin connectors:
See the graphic for the 10 pin connector circuit layout.
The injector power pin is the VPWR pin in the black 10 pin connector. [/b]
B.) Bad ECC power relay. The relay is on top of the computer, it provides power to the fuel injector system. This is relevant ONLY if you do not have power to all injectors.
It is somewhat difficult to get to, since it requires you to remove the computer from its 2 bolt mounting.. If the relay or socket is bad, you will not have 12 volts on any of the red wires in the engine compartment or to pins 37/57 on the computer. The pins 37/57 are the main power feed to the computer.
C.) Blown fuse link – The blue fuse link for the computer is up near the starter solenoid. Check for no 12 volts on the ECC relay socket or computer black/orange wires. No 12 volts and the fuse link is blown open. If the fuse link blows, there is no power for any of the computer functions.
D.) Bad wiring. Broken or damaged red wire to the chassis side of the 10 pin connectors.
Some basics about the computer:
Remember that the computer does not supply power for any actuator or relay. It provides the ground necessary to complete the circuit. That means one side of the circuit will always be hot, and the other side will go to ground or below 1 volt as the computer switches on that circuit.
2.) Get a noid light from AutoZone or other auto parts store, or even better a set of them.
This one is from http://www.summitracing.com/parts/oes-25142?seid=srese1&gclid=CMXk7M6dmM0CFdgOgQodGUMHWQ and costs about $6.
3.) Use the noid light to determine that the injector pulses and isn’t stuck in the on position.
It you have a set of them install all of them and compare the pulse intensity. Install the noid lights, turn the ignition switch to Run and crank the engine. A light that doesn’t pulse and stays on has a short to ground in the computer side of the circuit. That can be either a wiring fault or a failed computer.
If this is the case, remove the passenger side lick panel and disconnect the computer connector.
There is one 10 MM bolt holding it in place. Pull the connector all the way out of the computer so that you can see the computer side pins.
Disconnect all 8 fuel injector connectors from the injectors and leave them disconnected for steps 4-6.
Use the list from the graphic below to find the fuel injector pins for the injectors that didn’t turn the noid light off.
4.) Set the multimeter to low scale Ohms and measure between the computer ground located below the computer and the suspect fuel injector pins. You should see greater than 100 K Ohms resistance. If you see less than 100K Ohms, the wiring between the injector and the computer has an internal short to ground and needs service.
Check the harness and look for damage, kinks or frayed spots. A short to ground would result in an injector that never turned off.
5.) A single noid light that never turns on is either a wiring fault, or a failed computer. Either the injector has no DC power or the computer or wiring has failed and cannot switch the injector circuit to ground. Determine if the injector has power by using the multimeter to check for 12 volts on the red wire on the suspect injector connector. No 12 volts and you have a wiring fault.
If none of the noid lights flash and you have 12 volts at each injector, check to see that you have good spark. Before you even think about replacing the computer, see step 6.
Check the injector wiring for open circuit or broken wiring or bad connections.
Check the harness and look for damage, kinks or frayed spots. Check the 10 pin salt & pepper shaker connectors for bent pins, corrosion and damage.
Next check the fuel injector wiring for open circuits. Set the multimeter to low scale Ohms. Each fuel injector has a red wire (power) and a non-red wire (computer controlled ground).
Inside the car, take a short piece of 14 gauge bare wire and jumper it to the ground below the computer. Use the computer wiring diagram and select one of the injectors. The recommended procedure is to start with cylinder #1 and test each injector in numerical sequence 1,2,3, etc. Then stick the ground wire into the computer wiring harness socket for the injector you want to test. Don’t forget to move the ground inside the car each time you test a different injector.
Under the hood, set the multimeter to low ohms and ground one of the test leads to the engine block. Then measure the resistance between the non-red fuel injector wire in the fuel injector connector and the meter ground on the engine block. You should see less than 1 Ohm. More than that means a bad connection or bad wiring.
The 10 pin connectors are the first place to look for problems when it fails the above test.
Engine side testing Unplug the black 10 pin connector from its' mating half. Use the 10 pin connector diagram in this tech note to locate the injector you are currently testing. Measure the resistance between the non-red injector wire and the injector pin on the engine mounted side of the fuel injector harness; you should see 1 Ohm or less. More than that indicates a broken wire or bad connection.
Body side testing Use the 10 pin connector diagram in this tech note to locate the injector you are currently testing. Again, the black connector that is connected to the car body side of the wiring harness is the one to use for this test. Make sure that you test the injector pin for the wire side of the computer wiring harness pin that you grounded. Ground one lead of the multimeter on the engine block and check the resistance; you should see 1 Ohm or less. Test all 8 injectors in numerical sequence, and move the grounding wire at the computer wiring harness inside the car each time you test a different injector.
6.) Use an ohmmeter set on the low resistance scale and measure the resistance of each injector across the two contacts inside the injector electrical connector. You should see between 11-16 ohms. More or less than that is a bad injector. Next, measure between either one of the contacts and the metal on the injector body. You should see greater than 100,000 ohms. Don’t hold the metal probe tips with your bare hands when you make this measurement; It will give incorrect results if you do.
Once you have determined that the suspect injectors have good power and good wiring, the computer is the likely suspect, since a ground is required to complete a circuit and make it function. The computer provides the ground: if doesn’t, then the noid light will not flash. If the noid light stays on, the computer has an internal failure.
7) If you have gotten this far, then the problem is likely ignition related. Remember the noid test using all of the noid lights? All of them were supposed to be equally bright. Since you have already tested all the electrical side of the fuel injector circuit, the one remaining common item is the pip sensor inside the distributor. A failing pip sensor, damaged shutter wheel or bent distributor shaft could all cause the pulse delivered to the injectors to be faulty. A bad pip sensor will cause all the injectors not to fire and you will have no spark. Dumping the codes will usually show a code 14.
8) Spark plugs indicate one or more cylinders not firing: use the multimeter to measure the resistance of the spark plug wires. The wires should measure 2000 ohms per foot of length. A 2 foot wire would be 4000 ohms and a 3 foot wire would be 6000 ohms. Some Taylor and Accel wires have metal cores and will measure much less: that’s OK.
Next examine the spark plug wires very carefully for burn spots, cracks and damaged insulation. One good thing to try is to start the engine while the car is a very dark area, open the hood and look for sparks or blue glow. They indicate the electricity is leaking out of the spark plug wires.
Thanks to Tmoss & Stang&2birds at www.veryuseful.com/mustang/tech/engine/ for some of the graphics
Thanks also to www.oldfuelinjection.com for some of the graphics.
Attachments
Last edited:
08GT500
5 Year Member
@gstsaver
I'm fixing to dump a lot of very technical stuff on your plate, so you may want to print it out and highlight the sections that relate to your current problem.
Fuel injectors inoperative, one or more injectors either on all the time or will not squirt.
Revised 11 Aug 2018 to clarify injector wiring continuity testing
Tools needed: Noid light, Multimeter (volts & ohms), 10 MM socket &
extension, & ratchet.
Note: Do all of the steps and do them in order. The results of the subsequent tests are based on the prior tests being successfully passed.
1.) Each injector has a red power wire to provide power to the injector. Turn the ignition switch to Run and remove each injector electrical connector and use the multimeter to check for 12 volts on the red wire. Each injector should have 12 volts +/- .5 volt. More voltage is always better than less voltage. No 12 volts on a singe injector and the wiring for that injector is broken inside the engine fuel injector harness.
No 12 volts on all injectors:
A.) Check for a bad connection at the 10 pin connector. Check for 12 volts at red wire on the MAF or TAD/TAB solenoids mounted on the aft side of the passenger strut tower. Good 12 volts there and you have a wiring problem with the 10 pin connectors or associated wiring.
See the graphic for the location of the 10 pin connectors:
See the graphic for the 10 pin connector circuit layout.
The injector power pin is the VPWR pin in the black 10 pin connector. [/b]
B.) Bad ECC power relay. The relay is on top of the computer, it provides power to the fuel injector system. This is relevant ONLY if you do not have power to all injectors.
It is somewhat difficult to get to, since it requires you to remove the computer from its 2 bolt mounting.. If the relay or socket is bad, you will not have 12 volts on any of the red wires in the engine compartment or to pins 37/57 on the computer. The pins 37/57 are the main power feed to the computer.
C.) Blown fuse link – The blue fuse link for the computer is up near the starter solenoid. Check for no 12 volts on the ECC relay socket or computer black/orange wires. No 12 volts and the fuse link is blown open. If the fuse link blows, there is no power for any of the computer functions.
D.) Bad wiring. Broken or damaged red wire to the chassis side of the 10 pin connectors.
Some basics about the computer:
Remember that the computer does not supply power for any actuator or relay. It provides the ground necessary to complete the circuit. That means one side of the circuit will always be hot, and the other side will go to ground or below 1 volt as the computer switches on that circuit.
2.) Get a noid light from AutoZone or other auto parts store, or even better a set of them.
This one is from http://www.summitracing.com/parts/oes-25142?seid=srese1&gclid=CMXk7M6dmM0CFdgOgQodGUMHWQ and costs about $6.
3.) Use the noid light to determine that the injector pulses and isn’t stuck in the on position.
It you have a set of them install all of them and compare the pulse intensity. Install the noid lights, turn the ignition switch to Run and crank the engine. A light that doesn’t pulse and stays on has a short to ground in the computer side of the circuit. That can be either a wiring fault or a failed computer.
If this is the case, remove the passenger side lick panel and disconnect the computer connector.
There is one 10 MM bolt holding it in place. Pull the connector all the way out of the computer so that you can see the computer side pins.
Disconnect all 8 fuel injector connectors from the injectors and leave them disconnected for steps 4-6.
Use the list from the graphic below to find the fuel injector pins for the injectors that didn’t turn the noid light off.
4.) Set the multimeter to low scale Ohms and measure between the computer ground located below the computer and the suspect fuel injector pins. You should see greater than 100 K Ohms resistance. If you see less than 100K Ohms, the wiring between the injector and the computer has an internal short to ground and needs service.
Check the harness and look for damage, kinks or frayed spots. A short to ground would result in an injector that never turned off.
5.) A single noid light that never turns on is either a wiring fault, or a failed computer. Either the injector has no DC power or the computer or wiring has failed and cannot switch the injector circuit to ground. Determine if the injector has power by using the multimeter to check for 12 volts on the red wire on the suspect injector connector. No 12 volts and you have a wiring fault.
If none of the noid lights flash and you have 12 volts at each injector, check to see that you have good spark. Before you even think about replacing the computer, see step 6.
Check the injector wiring for open circuit or broken wiring or bad connections.
Check the harness and look for damage, kinks or frayed spots. Check the 10 pin salt & pepper shaker connectors for bent pins, corrosion and damage.
Next check the fuel injector wiring for open circuits. Set the multimeter to low scale Ohms. Each fuel injector has a red wire (power) and a non-red wire (computer controlled ground).
Inside the car, take a short piece of 14 gauge bare wire and jumper it to the ground below the computer. Use the computer wiring diagram and select one of the injectors. The recommended procedure is to start with cylinder #1 and test each injector in numerical sequence 1,2,3, etc. Then stick the ground wire into the computer wiring harness socket for the injector you want to test. Don’t forget to move the ground inside the car each time you test a different injector.
Under the hood, set the multimeter to low ohms and ground one of the test leads to the engine block. Then measure the resistance between the non-red fuel injector wire in the fuel injector connector and the meter ground on the engine block. You should see less than 1 Ohm. More than that means a bad connection or bad wiring.
The 10 pin connectors are the first place to look for problems when it fails the above test.
Engine side testing Unplug the black 10 pin connector from its' mating half. Use the 10 pin connector diagram in this tech note to locate the injector you are currently testing. Measure the resistance between the non-red injector wire and the injector pin on the engine mounted side of the fuel injector harness; you should see 1 Ohm or less. More than that indicates a broken wire or bad connection.
Body side testing Use the 10 pin connector diagram in this tech note to locate the injector you are currently testing. Again, the black connector that is connected to the car body side of the wiring harness is the one to use for this test. Make sure that you test the injector pin for the wire side of the computer wiring harness pin that you grounded. Ground one lead of the multimeter on the engine block and check the resistance; you should see 1 Ohm or less. Test all 8 injectors in numerical sequence, and move the grounding wire at the computer wiring harness inside the car each time you test a different injector.
6.) Use an ohmmeter set on the low resistance scale and measure the resistance of each injector across the two contacts inside the injector electrical connector. You should see between 11-16 ohms. More or less than that is a bad injector. Next, measure between either one of the contacts and the metal on the injector body. You should see greater than 100,000 ohms. Don’t hold the metal probe tips with your bare hands when you make this measurement; It will give incorrect results if you do.
Once you have determined that the suspect injectors have good power and good wiring, the computer is the likely suspect, since a ground is required to complete a circuit and make it function. The computer provides the ground: if doesn’t, then the noid light will not flash. If the noid light stays on, the computer has an internal failure.
7) If you have gotten this far, then the problem is likely ignition related. Remember the noid test using all of the noid lights? All of them were supposed to be equally bright. Since you have already tested all the electrical side of the fuel injector circuit, the one remaining common item is the pip sensor inside the distributor. A failing pip sensor, damaged shutter wheel or bent distributor shaft could all cause the pulse delivered to the injectors to be faulty. A bad pip sensor will cause all the injectors not to fire and you will have no spark. Dumping the codes will usually show a code 14.
8) Spark plugs indicate one or more cylinders not firing: use the multimeter to measure the resistance of the spark plug wires. The wires should measure 2000 ohms per foot of length. A 2 foot wire would be 4000 ohms and a 3 foot wire would be 6000 ohms. Some Taylor and Accel wires have metal cores and will measure much less: that’s OK.
Next examine the spark plug wires very carefully for burn spots, cracks and damaged insulation. One good thing to try is to start the engine while the car is a very dark area, open the hood and look for sparks or blue glow. They indicate the electricity is leaking out of the spark plug wires.
Thanks to Tmoss & Stang&2birds at www.veryuseful.com/mustang/tech/engine/ for some of the graphics
Thanks also to www.oldfuelinjection.com for some of the graphics.
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