'92 F-150. A month ago, it died in traffic. Checked for fire, and had none. Towed to indy shop, diagnosed with bad control module, replaced module, cap, rotor, and plug wires,and all was well -- for a week --, then stranded on the side of the road. Back to the shop, module checked good, they kept it a week, claimed to have checked everything, and claimed to have replaced coil.

Mechanic(?) called and told me the truck was running, but he had never been able to figure out why; nothing he had tried worked, but it was running, and I could pick it up. Didn't get the eight miles to my home, and dead on the road, again.

This time, I had it towed home. Checked everything I could think of. Finally took the coil off -- it was the original and had not been replaced by the shop, so I went to Autozone, bought a coil, put it on, and the truck ran like a top. This morning, it wouldn't start. Found an old coil that I knew was good, jumped it into the system, and got fire. Took the Autozone coil back, they tested it, and it checked good. Gave me a new one, anyway, though.

Put the replacement coil on, and just like the last time, bingo! Four hours later, truck won't hit a lick. No fire. Too near dark to fool with it, but will start over, in the morning.

What is keeping me up, tonight, is the possibility that the man at Autozone was right, and that first coil was good, and if that might indicate a corroded or broken lead to the coil. Maybe all I have been doing is manipulating a bad wire while changing out coils, and I need to track down an occasional open.

Does this make any sense at all? What would you suggest? Anybody? I'm getting really sick of this puppy, but it's all I've got.

TIA

 

A weak Hall effect pickup in the distributor, bad grounds, or both can create an intermittant problem like this. You start swapping parts, ripping apart harnesses, etc, and the problem "fixes itself". You smugly pay yourself on the back. The next day (or week) the problem comes back. Sometimes changing the TFI module seems to "fix" it, but only because it is more tolerant of ground shifts or a bad pickup.

It took me all last summer to track this down on my truck. Cleaning the grounds improved it markedly, but in the end the real fix was replacing the Hall effect coil in the dizzy.

 

My guess would be the stator inside the distributor. Testing it probably wouldn't do any good because if it was in a running condition it would likely test good regardless. I'm sure the '92 has a newer style ignition system than the known '87 through '90 systems that I have come to know better than the back of my hand. But I believe the same basic parts are there. I learned that when there is an intermittent ignition problem, the most likely culprits are the ignition module, the coil and the stator. The first two you have already replaced. Anything would be a guess, the stator is my guess. Good luck.

 

Okay, a couple of questions. This is a 6-cyl engine. Firstly, is there a difference between the Hall effect pickup and the stator? I'm a little tentative about removing the distributor, but could handle that with a little coaching. Is a Hall effect pickup (or stator) usually available, or would I be better off with a new or rebuilt distributor?

I'll check and clean the grounds, first, and check for continuity. If the floorboards hadn't rotted out, I'd still be driving my '66 with the 300-6. That was a simple fuel, air, fire, compression arrangement that was much easier to understand and tweak.

Thanks for all the help.

 

Turns out the second coil, from Autozone was bad. Picked one up at NAPA, and got the old gal running. This truck has over 200K miles, so I'm replacing the distributor, next weekend.

Thanks for the help.