I love those guys....generally can buy those cars for pennies on the dollar if they don't start parting them out...... Hell my current beater is a 93 4cyl dressed as a 93 gt, It was a cluster, now no one would have a clue unless they checked the vin or I pointed it out.. if the 8th didgit isn't E you might have a headache on your handsI hate people that 'think' they can slap on this or leave that off and then when it doesn't go right they sell it off for someone else to deal with.
Now that you're 'the one' we need you to verify some things so we can help you get this 'mid life mess' running right.
Verify what computer is in the car, and if the car is actually an original V8 GT car. We can go from there.
8th is E on this rig.I love those guys....generally can buy those cars for pennies on the dollar if they don't start parting them out...... Hell my current beater is a 93 4cyl dressed as a 93 gt, It was a cluster, now no one would have a clue unless they checked the vin or I pointed it out.. if the 8th didgit isn't E you might have a headache on your hands
When you swapped out the intake did you reconnect the ground wire and when you did the swap you put the corresponding bottom ?Ok
So
Lookin for advice.
89 GT 5.0 Edelbrock intake (all I know Mod wise)
Bought Ford Code reader
Got a 23 TPS is all for now
Also 98 ON the KOEO test.
Car works ok
Pulls hard
Needs a set of rear clutches (1 wheel spin)
Idle surges a bit.
Fuel pump goes 2-3 Seconds then off at KO
Any away
My main issues is that she won’t start sometimes after running for 30 mins.
Cranks OK
won’t fire up.
If I disconnect Bat for 5 mins (something clears)
Car fires right up.
I have not done the idle Surge/start checklist yet as I dont think I’ll find anything obvious.
Looked for vacuum leaks
Changed CTS/Coolant sender and TFI so far
Likely put a new TPS on as well..
Car has Cold intake
MAF removed (heard that’s OK with the intake that’s on it now..
Thanks for reading folks
Just looking for new places to look..
Awesome post,When you swapped out the intake did you reconnect the ground wire and when you did the swap you put the corresponding bottom ?
Maybe instead of going by the words of the grapevine you should go to the source...Theres lots of TECHNICAL INFO TO KNOW BEFORE INSTALLATION...
On my Edelbrock intake #3881 theres a snowballs chance in hell that both would mate up perfectly as the stock intake has oval ports and the Edelbrock intake has rectangular ports...
Its been years but from what I remember my buddy had a EFI performer intake too and when he installed it he had problems but found out he failed to install a baffle plate and didnt install the egr plate either....Both parts mentioned plus all emissions hookups were definately needed to be hooked-up after calling Edelbrock fuming and finding out the old owner of the intake was the problem because he bought it used off craigslist and actually should of bought a new one because the missing parts costed him a pretty penny and 5 weeks time to get them........LOL
When the intake was swapped out there were a number of things that got disconnected..Id go back and inspect every plug that was pulled because sometimes those connectors dont go back on all the way but feel like they hit home....The MAP BAP TPS also TFI module and AIT sensor plugs are famous for this...
Like others have said you need the MassAirflow sensor ...Its the primary form of measurement and the TPS becomes a slave to it...You kinda need the BAP too unless you put a resistor or have a chip w/tuner program......
Once you disconnect the MAF the ECU is supposed to go into Limp Mode if the BAP and TPS sensors are good.........
With the EEC-IV system when my MAF totally fails I dont get a code...I only get a code for the MAF if the power or signals arent processing correctly with-in the ECU which is weird but from memory I think it has its own internal chip too making it kind of a standalone sensor even though its wired in and sensed by the ECU the ECU goes by the MAF's parameters that are programmed in so if you use a different size MAF youre gonna have to get a chip and do a MAF transfer profile enhancement or find someone who can erase your bin file and burn a new one with proper changes........
Another thing to note is I recently was informed that Moates is discontinuing their chips, chip repairs also technical support and going into retirement so the only alternative is the non-EEC-IV based but in a EEC-IV case ;- The Pimp Megasquirt system..........
The way I know when my MAF isnt working is by hooking up my laptop to it and use my Moates dashboard to read the voltage or hooking it up to my Matco OB2 reader and right now I bet youre saying that the EEC-IV is OBD1 and it is- but with one of these adapters below I can use the PID from the Matco handheld and a download from the internet to read vehicle vitals as its running and even not running plus I also go right to the MAF when my vehicle starts up and instantly shuts off like the battery in my QH chip died or starts up and instantly bogs down and shuts when the throttle is cracked like I lost fuel pressure........
A friend of mine bought an 89 and the old owner changed the longblock out and when removing the engine he mustve snagged the MAF plug on the block when yanking the engine out because the wires under the loom were stretched so badly there was literally 3 strands on 2 wires making the flow of juice not happen right and wasnt too good but with a multimeter the problem was found because those wires showed high resistance plus they intermingled when I did a cross-wire test on the other wires on the MAF plug....
Alls you have to do is disconnect the ECU plug from the ECU and use this schematic starting at pin #1 go down the line pin by pin with one probe and hook the other probe to its corresponding termination to see if you get an audible beep and then touch the other pins to make sure theyre not melted or rubbed raw somewhere in the harnesss causing a short to the same wire.....
Another problem area are the Salt and Pepper shakers......10-12 years ago on another buddies car his connectors were a lil toasty due to a brake fluid fire and he needed to repin every wire in both connectors both male and female sides but opted to use solder and shrink tubing to hardwire the ECU harness to the Injector harness.......
It took a lil bit using a cheap Radioshack 40watt soldering iron outside in 50 degree weather but the car actually ran way better than before the fire too.....
Good Luck
The two connectors not plugged in by the intake pipe where a maf would be look like the a/c cut out relay by the tower and the round one looks like its for the purge solenoid but I'm going of memory and haven't messed with an 87-88 SD wiring harness in years
Will an 87/88 ECU harness connect to the 89 dash harness correctly? I want to say 87-90 have the two plugs by the booster so should be okay physically connecting up but what about pinout?
I’m gonna look for some numbers today on the harness.1988 would probably work fine with an 89 dash harness as MAF was available that year in CA.
1987 might not work because there were some differences in how Ford routed the pin 30 that year vs 88+.
As a general rule, one should try and keep all harnesses from the same year. Ford did some slight changes here and there over the years and all it takes is one wire not being present to cause issues that cause people to throw in the towel on a project car and sell it to the next guy when they can’t figure out why it won’t run right
short post??Well then, you'll love this!
Key thing with Speed density cars is the Map sensor and the vacuum tubing connected from it to the intake manifold. If the are any leaks there you will never get it tuned. Unfortunately without an oscilloscope you can only make sure it has the correct incoming voltage (@map). EEC adjusts fuel and spark based on manifold vacuum or lack there over when you press the right pedal. Have you tried idling it with the tps unplugged? Set idle to roughly 625-650 rpm IAC and spout unplugged 10 degs base timing, factory set point is 672 rpm and it will try to get by any means possible, (birthplace of idle surge) Do this only when car is warmed up above 160 or else the eec will be adjusting down to desired idle speed and timing and your idle will change until up to temp. That will get you close to 25-30% duty cycle on the IAC. That is where you want to be regardless of tps voltage.This and base timing will be key to drivabilty and idle. Think of IAC as a slow trim and timing as a fast trim. EEC will do most of idle adjust with timing and IAC to smooth it out. If you open throttle blade too much IAC will be too low in the duty cycle to react fast enough and you will suffer dying/unable to hold idle, same with TB closed too much, duty cycle will be to high and you might get hanging idle from rev down and surge. Without going down the rabbit hole of the IAC function, just be happy understanding that the fox bodies EEC IV are designed to run off of a predetermined quantity of air measured in kg/hr, it is the same in both SD and MAF. MAF measures this across a heated wire that affects voltage with air flow, SD does this with modulated wave assigned to manifold pressure/vacuum changes (MAP sensor), spark and fuel tables are pretty much the same for both just go about it differently. Ford figured out exactly how much air the TB and IAC flow at base idle of 672 and 25-30% duty cycle and wrote the code for the sensors to follow that as law. This is where HCI and injectors and throttle body swaps get tricky or bad sensors kill you, as with out correct emulator and software you are blindly trying to get back to that magic 20.41 kg/hr at 672rpm TB/IAC combined flow. You can't see duty cycle without a QH, MS, or Tweecer and a laptop and happens too fast to see with a digital meter. It is a pulsed 12vdc signal. Speed density is simplicatally complicated, meaning less parts than MAF cars, but more important to get set right. Vacuum leaks are your nemesis when it comes to speed density foxbodies esp. Give them no quarter. To be effective in tuning these cars you first have to understand why they are unhappy in the first place. Without this understanding, you are simply jerking off. If you both work together the eec platform can do great things, but a Quarterhorse is a must have item if you change anything other than spark plugs and oil with these cars. I know I have said a lot but, each statement was a lesson hard learned, if I can help you to not go thru that heartache, then my troubles were not in vain. Only things factory left in my car are the forged short block minus cam and the axle tube. Nothing crazy but enough to cause headaches with factory tuning. Mine holds 800 ish rpm just nice with MAF conversion and tune. Got too complicated to make happy with SD and no tune. Let me know what you find out with your testing of grounds and sensors. I will try to check back on the reg. There is a book on EEC IV theroy, if you care to dig deeper and EFIdynotuning.com is an excellent resource. I can't understate the need to know why before you try the how, enough. Also, download as many drawings and diagrams as you can find and put in all in one file. Most all of it is in here if you search for it. Thank you for taking the time to read this short post, if I had more time, I would've written a longer one......
ALSO, WHEN I HOOKED UP THE code reader, I was given a 6 (cyl)
Then next time a 4 (cyl)
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