Strange No Start Condition

[General karthief]

What I'm having trouble getting my head around, is that the only symptom I know for sure is when the negative signal to the coil stops from the ICM (#5 Pin) as the car is running, and the car dies immediately with no spark, even at higher RPMs (verified by timing light on coil wire).

When I try to restart with the key still in the run position (without cycling key off first):
- The PIP signal remains okay, based on the LED flashing signal on the #1 Pin,
- I still have 12v to the coil on #4 pin,
- I still have 12v ground on the #6 Pin,
- There is no #5 Pin signal, and the car won't restart (cranks fine, just no spark).

However, when I cycle the key from run to off, and then back on again to the start position, the #5 Pin negative signal works again, and the car immediately starts.

Like I said, I'm not great with electrical issues, but I can't seem to get around the reality that the negative #5 Pin signal fails from the ICM, and won't reset without the ignition key cycling off-on again. This is 100% repeatable.

With constant 12v and ground connections to the distributor, what does cycling the key actually reset to get spark again?

Sorry for rambling, but I'm running my mind in circles, and won't have time to finish the negative ground testing for the next week or two.

Thanks again.

 

[General karthief]

This is a copy of a problem that is in the cranks but no start checklist thread, I hope @rbrown777 can get some feed back here,
His original post with specs on his car.
Car dies, then cranks with no spark.

Hi guys, tagging on as a new member.

After doing a lot of reading through these threads, it's obvious that a lot of people have the same issues with these Ford ignitions. However, it doesn't seem like I'm finding the right solution. I've been through the No Spark tests, but not sure about the results.

The problem started a couple weeks ago, when I replaced my Motorcraft (original DY1074) TFI module, due to a problem with bad spark at high RPM. The new Motorcraft DY1284 module (supercedes the DY1074 from what I understand) made the car feel very strong to 6k RPM. I thought the problem was fixed, and all was good. However, 2 days later, my mustang left me stranded on the highway, and wouldn't restart. I had it towed home, and after some research, decided I had another bad TFI.

I replaced the TFI module, and also bought a rebuilt Motorcraft distributor (in case the PIP sensor was the problem).

This new TFI and distributor ran great, for about an hour. Then died again. I could restart and run for a moment at a time, and was able to limp the mile back home.

Rather than throwing more parts at it, I have been running diagnostic tests (Voltage checks, LED test light), and keep coming up with the same test results. So...I replaced the TFI again, and it died within 30 minutes.

Here's what I've found:
- After the car warms up, it dies like it was turned off with a light switch.
- If I try to restart by leaving the key in the run position after it dies (WITHOUT cycling the key off first), it won't spark at all (verified by timing light on coil wire).
- This seems to be an important part of my ignition problem.
- If I try to restart by turning the key all the way off, and then back on, it starts again (but dies again moments later showing no spark).
- Once the engine cools off, it will run for awhile before it dies again.

Tests:
- I have 12v to both sides of the coil, whether spark or no spark condition.
- When the car is in the 'no spark' mode, I have:
- Battery is fully charged, and never a problem cranking
- 12v power to the ICM
- LED signal flashing from the PIP while cranking, which tells me the PIP is okay
- No LED signal from the ICM to the coil while cranking
- I have 12v ground at the ICM
- Will not start w/spout removed (PIP test)
- When I cycle the ignition key off and then on again, I get the LED signal from the ICM to the coil. Car will start, with or without spout connected (just dies again shortly).

I'm on my 4th TFI module, and my 2nd distributor (all Motorcraft), and even switched out a known working coil. Everything I see is pointing to a bad TFI module, but I'm having trouble believing that all these modules are bad.

I've thought about moving the TFI to another location, but I want to make sure of the problem before spending any more on parts.

Any troubleshooting assistance would be appreciated.

A little about the car:
1992 Notchback, newly rebuilt 5.0
10.5:1 forged pistons, Balanced rotating assembly
Motorsport GT40 X303 aluminum heads, professionally ported
F303 Cam w/1.72 roller rockers
Motorcraft distributor & Coil
3G Alternator w/4GA cable/fuse kit
255LPH Fuel pump, 24 lb/hr injectors
BBK 70MM TB, Pro-M 80mm Mass Air Meter
Cobra 13" front/11.65" rear disks, SN95 Master Cylinder & booster
AJE K member, SN95 A-Arms, 5-lug spindles/axles,
2004 Cobra power steering rack, MM Hybrid steering shaft
Tokiko adjustable struts/shocks
T-5, Cobra clutch, 3:73 gears, Motorsport Aluminum drive shaft
320 RWHP / 333 RWTQ

 

[Johnnycleveland]

Hey Karthief, I just saw this thread after a long night of diagnostics on the exact same condition in my 88 XR7. I have gone through new PIP, two TFI, ignition switch, plugs, wires etc. We have done all the tests there are, break out box, ECM monitor, LED light on the dash, tests on every wire from TFI, three coils, two Ford coils from working cars and still nothing to shake a finger at. I feel kind of silly going to Ford for another TFI probably for the same reason you wont, I'm sure they'd look at me in disbelief. So I just ordered a new dizzy with everything included, a drop in from NAPA, for less than the cost of a Ford TFI. This 218.00 bucks just to satisfy my curiosity. After all this testing and gathering "data" we simply don't know where else to look, yet. I just thought to join the forum to share my woes with you, with the hopes of helping each other out of this nightmare. If you should want to keep in touch. [email protected] I would like to know if and when you achieve suxess, and how of course. The race is on. Mind you, I started dealing with this three years ago, off and on, as I store the car for winter months. Ciao.

 

[General karthief]

Is the xr7 a 5.0 ho?
Go through the cranks but no start checklist in the tech/how to section, it sounds like you've covered most for it already but the list really needs to be done in order.
I don't know if mercury had/has the same ignition switch problems that the fox had but it's woth checking out too.

 

[Johnnycleveland]

Yes XR7 is 5.0 In the 88 diagnostic shop manual, 3" thick, we went through every flow chart. These are the same for all 88 Fords cars and trucks. These tests were conducted with the breakout box for pin point measuring. Later, we hooked up the ECM monitor with correct overlay and a 4" manual that comes with it and went through all of it again according to the procedures outlined therein. We can see all kinds of signals with that gismo. Injector firing, PIP, IDM, Spout, etc. It has a switch that allows me to go from computer timing to distributor timing and it runs smoother in distrib. timing, bypassing the EEC. So I ask my guy, Do I get a new computer now? NO. Not yet. He/we have all kinds of reasons and data that points to the TFI. Again! Prior to the LED lamp stuck to the dash, we had a peanut bulb to monitor cranking activity. It would light upon cranking but would not start. Then we had this idea to pull the bulb as we cranked and lo and behold it starts, immediately. Repeatable without deviation. Conclusion? What ever minute draw from the peanut bulb caused a no go. Not enough coil input to produce an output? I still must cycle the key to off to reboot and restart. Sorry for blabbing. I'm going to pick up the new dizzy today and we'll see what happens. Any luck on yours??

 

[General karthief]

I reposted for @rbrown777 he was having this problem and pm'd me.

 

[Johnnycleveland]

This is a copy of a problem that is in the cranks but no start checklist thread, I hope @rbrown777 can get some feed back here,
His original post with specs on his car.
Car dies, then cranks with no spark.

Hi guys, tagging on as a new member.

After doing a lot of reading through these threads, it's obvious that a lot of people have the same issues with these Ford ignitions. However, it doesn't seem like I'm finding the right solution. I've been through the No Spark tests, but not sure about the results.

The problem started a couple weeks ago, when I replaced my Motorcraft (original DY1074) TFI module, due to a problem with bad spark at high RPM. The new Motorcraft DY1284 module (supercedes the DY1074 from what I understand) made the car feel very strong to 6k RPM. I thought the problem was fixed, and all was good. However, 2 days later, my mustang left me stranded on the highway, and wouldn't restart. I had it towed home, and after some research, decided I had another bad TFI.

I replaced the TFI module, and also bought a rebuilt Motorcraft distributor (in case the PIP sensor was the problem).

This new TFI and distributor ran great, for about an hour. Then died again. I could restart and run for a moment at a time, and was able to limp the mile back home.

Rather than throwing more parts at it, I have been running diagnostic tests (Voltage checks, LED test light), and keep coming up with the same test results. So...I replaced the TFI again, and it died within 30 minutes.

Here's what I've found:
- After the car warms up, it dies like it was turned off with a light switch.
- If I try to restart by leaving the key in the run position after it dies (WITHOUT cycling the key off first), it won't spark at all (verified by timing light on coil wire).
- This seems to be an important part of my ignition problem.
- If I try to restart by turning the key all the way off, and then back on, it starts again (but dies again moments later showing no spark).
- Once the engine cools off, it will run for awhile before it dies again.

Tests:
- I have 12v to both sides of the coil, whether spark or no spark condition.
- When the car is in the 'no spark' mode, I have:
- Battery is fully charged, and never a problem cranking
- 12v power to the ICM
- LED signal flashing from the PIP while cranking, which tells me the PIP is okay
- No LED signal from the ICM to the coil while cranking
- I have 12v ground at the ICM
- Will not start w/spout removed (PIP test)
- When I cycle the ignition key off and then on again, I get the LED signal from the ICM to the coil. Car will start, with or without spout connected (just dies again shortly).

I'm on my 4th TFI module, and my 2nd distributor (all Motorcraft), and even switched out a known working coil. Everything I see is pointing to a bad TFI module, but I'm having trouble believing that all these modules are bad.

I've thought about moving the TFI to another location, but I want to make sure of the problem before spending any more on parts.

Any troubleshooting assistance would be appreciated.

A little about the car:
1992 Notchback, newly rebuilt 5.0
10.5:1 forged pistons, Balanced rotating assembly
Motorsport GT40 X303 aluminum heads, professionally ported
F303 Cam w/1.72 roller rockers
Motorcraft distributor & Coil
3G Alternator w/4GA cable/fuse kit
255LPH Fuel pump, 24 lb/hr injectors
BBK 70MM TB, Pro-M 80mm Mass Air Meter
Cobra 13" front/11.65" rear disks, SN95 Master Cylinder & booster
AJE K member, SN95 A-Arms, 5-lug spindles/axles,
2004 Cobra power steering rack, MM Hybrid steering shaft
Tokiko adjustable struts/shocks
T-5, Cobra clutch, 3:73 gears, Motorsport Aluminum drive shaft
320 RWHP / 333 RWTQ

 

[Johnnycleveland]

I'm on my 4th TFI module, and my 2nd distributor (all Motorcraft), and even switched out a known working coil. Everything I see is pointing to a bad TFI module, but I'm having trouble believing that all these modules are bad.

I had the same difficulty. Believe it. Replaced TFI twice this summer DY-1284 in vain. Today I put in a new NAPA dizzy # DIS42892MA because I had read from others on other forums that Ford TFIs were indeed bad. I am delighted to report that all seems well now with new, complete dizzy. Even the spedo stopped jumping around. I don't know if it's too early to have a party but, I just ran the car pretty hard for about an hour, lights on sound system jacked, idled in driveway 15 min when I came home and..........PERFECT, whereas, night before last it died three times in less than half mile. But, tomorrow is another day. I will report back if there are any changes.

 

[jrichker]

Yes XR7 is 5.0 In the 88 diagnostic shop manual, 3" thick, we went through every flow chart. These are the same for all 88 Fords cars and trucks. These tests were conducted with the breakout box for pin point measuring. Later, we hooked up the ECM monitor with correct overlay and a 4" manual that comes with it and went through all of it again according to the procedures outlined therein. We can see all kinds of signals with that gismo. Injector firing, PIP, IDM, Spout, etc. It has a switch that allows me to go from computer timing to distributor timing and it runs smoother in distrib. timing, bypassing the EEC. So I ask my guy, Do I get a new computer now? NO. Not yet. He/we have all kinds of reasons and data that points to the TFI. Again! Prior to the LED lamp stuck to the dash, we had a peanut bulb to monitor cranking activity. It would light upon cranking but would not start. Then we had this idea to pull the bulb as we cranked and lo and behold it starts, immediately. Repeatable without deviation. Conclusion? What ever minute draw from the peanut bulb caused a no go. Not enough coil input to produce an output? I still must cycle the key to off to reboot and restart. Sorry for blabbing. I'm going to pick up the new dizzy today and we'll see what happens. Any luck on yours??

There is two electronic terms input impedance and source impedance that covers what you saw. A incandescent lamp (low input impedance) has much more current draw than an led (high input impedance) .

When you draw excessive current, the source voltage drops. This is because the source impedance is high when compared with the load device (lamp, actuator, motor, etc.). High input impedance needs to used when a high current draw would cause an excessive voltage drop. A Voltmeter is an example of a device with a high input impedance. It draws a very minimum amount of current so that it does not load a circuit and cause a voltage drop.

Low source impedance devices provide high output current and are not so sensitive to current draw. A car battery is an example of a low impedance source device. You can draw large amounts of current before you have any significant output voltage change.


To get the maximum efficiency, the impedances need to be closely matched. High source impedance needs to be paired with a high input impedance. Low source impedance news to be matched with low input impedance.

The TFI trigger circuit is an example of a high source impedance and a high input impedance circuit. Draw more current than the circuit was designed to provide, and the voltage in the circuit drops below proper operating level.

It all goes back to Electronics 101 - Ohms Law.

 

[Johnnycleveland]

I'm on my 4th TFI module, and my 2nd distributor (all Motorcraft), and even switched out a known working coil. Everything I see is pointing to a bad TFI module, but I'm having trouble believing that all these modules are bad.

I had the same difficulty. Believe it. Replaced TFI twice this summer DY-1284 in vain. Today I put in a new NAPA dizzy # DIS42892MA because I had read from others on other forums that Ford TFIs were indeed bad. I am delighted to report that all seems well now with new, complete dizzy. Even the spedo stopped jumping around. I don't know if it's too early to have a party but, I just ran the car pretty hard for about an hour, lights on sound system jacked, idled in driveway 15 min when I came home and..........PERFECT, whereas, night before last it died three times in less than half mile. But, tomorrow is another day. I will report back if there are any changes.

I'm on my 4th TFI module, and my 2nd distributor (all Motorcraft), and even switched out a known working coil. Everything I see is pointing to a bad TFI module, but I'm having trouble believing that all these modules are bad.

I had the same difficulty. Believe it. Replaced TFI twice this summer DY-1284 in vain. Today I put in a new NAPA dizzy # DIS42892MA because I had read from others on other forums that Ford TFIs were indeed bad. I am delighted to report that all seems well now with new, complete dizzy. Even the spedo stopped jumping around. I don't know if it's too early to have a party but, I just ran the car pretty hard for about an hour, lights on sound system jacked, idled in driveway 15 min when I came home and..........PERFECT, whereas, night before last it died three times in less than half mile. But, tomorrow is another day. I will report back if there are any changes.

 

[Johnnycleveland]

Hello boys and girls. It's been a couple of weeks since I replaced the dizzy and the XR7 has been running flawlessly. I though I'd share this intell in the hopes that it will be of some help to someone going through the TFI hell I went through. Cheers.

 

[General karthief]

Thanks for the update, I was wunder'n
but I was running out of popcorn
Glad you got it sorted out.

 

[larrym1961]

Motorcraft DY1284 TFI's are junk made in China. I had a MSD TFI last longer than a DY1284 if you can believe that.

 

[Johnnycleveland]

Yea, after extensive testing with the second TFI I still had difficulty believing we had another dud from Ford, even though every test pointed in it's direction. A mind of epic proportions!

 

[imp]

I keep seeing "dizzy"; forgive my ignorance and please inform me what the hell is a "dizzy"??
imp

 

[General karthief]

I don't know what to tell ya imp, it's cute for distributor, some would say it's 'short' for distributor but I say it's cute. Like say'n nos for nitrogen oxide. I think the ricer kids called it that because the bottles had NOS on them, most could'n read and didn't know that was the abbreviated name of a company.
I guess someone thought that up because you 'chase your tail' when it malfunctions, or they are like me and can't speel, ah, crap, hit spell check, can't spell. There fixed.

 

[Johnnycleveland]

Ha, "chase your tail" I like that. It must be the whirl wind in the mind caused by all the data and diagnostic sequences, repeating test that have already been performed because we second guess ourselves because we are not scientists in a lab and we don't record the conclusion of a test and move on to the next. LOL at least, I am defiantly not that organized in the head. Ya get dizzy!