Electrical Issues. Help before I kill it!

[Diabolic]

My 95 Cobra will just randomly die when driving down the hwy for about 1-3 seconds then come back on like nothing was ever wrong. In my datalogs almost everything drops to zero.

Spark base=0
TP Rel=0
timing drops to 0
MAF Voltage goes to 0
Hego's show 2.6 volts
RPM logs 0

Today it did this and I tried to free rev the car with the clutch in. It felt like I was reving against the factory limiter at 3000 rpm. Cycled the key off to on and she ran perfect for another 5 mins. It's completely random. Anyone think the pickup or the TFI could cause this? It has done this a few times in the past but I thought it was a miss caused by bad wires, corroded cap, worn plugs etc....... I just replaced the ignition setup with and MSD 6AL, MSD Coil, MSD cap and rotor, new plug wires, and new plugs. Same issue, but seems to be getting worse. I tried uploading 3 different tunes with the same result. Maybe the Moates QH is going bad? I ordered a chip so I could burn it and remove the QH next week. For some reason I'm leaning towards TFI or Pickup in the dizzy. They control spark, fuel, etc.....right?

[turbos66coupe]

My car did this and it was because the QH died, also a 95. Check codes mine had a memory failure code in it

[Diabolic]

Its not the QH, I pulled it and installed a chip in it's place. This time the car finally died at idle. The fuel pump continues to run and the injectors keep firing! You can hear them spraying and going click, click, click! I've owned many Ford EFI cars and never ever had something like this happen. Guess I'm just lucky. Bad ECM, Bad TFI?

[03silversnake]

Its not the QH, I pulled it and installed a chip in it's place. This time the car finally died at idle. The fuel pump continues to run and the injectors keep firing! You can hear them spraying and going click, click, click! I've owned many Ford EFI cars and never ever had something like this happen. Guess I'm just lucky. Bad ECM, Bad TFI?

Same thing happen to me an it was my fuel pump.

[SMEGMA STENCH]

Check your pickup coil in the dist. There is a factory defect that almost all the GT's and cobras have.

[Diabolic]

I'm not one to throw parts at a car. How do I test the pickup? If the injectors keep firing after the car has stalled and the fuel pump stays running then what parts control that? Would a defective injector driver in the ECM cause the issue? Can the TFI even send a signal if the dizzy isn't spinning? Same question applies to the pickup coil.

[Diabolic]

Anyone have a dizzy from a 94 or 95 I can try?

[SMEGMA STENCH]

You can find out what output the pickup coil is supposed to have, (somewhere online i presume) and test for that using a multimeter/voltage meter. I am not one to throw parts at a car either thats why i suggested that cause its fairly easily tested. IIRC, if your car doesn't run or won't stay running long enough, you just need someone to sit there and crank the engine while you perform this test .

I went through this and about pulled my hair out till a buddy told me about that defect. So i just thought id mention it. Now i have witnessed several other cars that had it. All were 94-95 GT/Cobras

[Diabolic]

My buddy dropped off his spare TFI and dizzy. Hopefully Monday I can get the dizzy stabbed and see if that fixes the issue. TFI will be next, followed by an ecm.

[turbos66coupe]

Try tfi first its easiest. Also you can pull the little cover off the tfi and look for big bubbels in the film. That's an indication it got to hot. Tfi is more likely than dist.

[SMEGMA STENCH]

Never heard of the TFI. What is that ?

[FoxBodyNick]

Never heard of the TFI. What is that ?

Thick film ignition module. Controls spark output.

[Diabolic]

I have read the schematics several times and I can't see how any one part other than the ECM could control both the injectors and fuel pump. I'm bench mechanicing because I haven't had time to work on it yet, but I'm convinced it's the ECM. My datalogs going blank when it stumbles further reinforces this belief.

[greenbullitt]

I have read the schematics several times and I can't see how any one part other than the ECM could control both the injectors and fuel pump. I'm bench mechanicing because I haven't had time to work on it yet, but I'm convinced it's the ECM. My datalogs going blank when it stumbles further reinforces this belief.

replace the dizzy. Ive seen some pip (hall effect) die recently, my best guess without seeing it. If the pip dies, fp and all dies

[Diabolic]

Yep, new dizzy and she's good to go! It was crazy hearing all the injectors pulse after the car was shut off. First time for me.