I was driving fine and went to pass a Amish buggy and there was a little hesitation and sputter. Kept driving fine then stopped at a Kmart set there for 5 minutes and she shut off. Turned the key it cranks and fry's to start but just can't. I'm a long ways from home so please help. 86 f150 efi 5.0-

 

Let it cool off for a couple of hours and see if it restarts and runs fine later. If it does, this is a classic symptom of a dying ignition control module.

However, it could also be a few other things, too, so see what happens in a while and report back.

 

Do you have someone to help you? Get someone to crank the engine while you test for spark. You can get one of those spark testers at the store, or stick a screwdriver up in one of the wires and hold the shank close to a piece of metal while someone tries to crank the engine. You should see a spark jump from the screwdriver to the engine block.

 

I let it sit for awhile and went back to it and it started right up. Let it sit over night and just drove it home. After about half hr of driving it started sputtering and hesitating every time I'd have to speed up to go up a hill or after stopping and starting. If I'm on flat surface with a steady pedal it drives fine

 

I would take it to a parts store and have the ignition module tested (you'll need to remove it from the vehicle to do that) you can replace it in their parking lot if it's bad but you'll also need a special wrench (5.5mm thin-wall socket).

If the problem is, in fact, a dying ignition module, the engine will eventually refuse to start at all.

 

Running ok on the level but not pulling a hill is frequently an ignition problem, and it is caused by the spark finding an easier place to jump to ground than through the wires and into the plugs. But, the ignition module usually fails completely, killing the ignition completely. Bad plug wires can cause that symptom, as can a bad rotor or distributor cap.

 

Eventually, yes, a failing ignition module will burn out and fail completely. In my experience, and that of NumberDummy's and the NHTSA, they give some warning ahead of time:

Yes, he's specifying the DuraSpark module in his quote, but the same applies to the distributor-mounted TFI modules (Ford was sued by the NHTSA over these failures).

 

In this case you might just have to buy another module. I am not sure if the module will fail in the store after it cools off, but it might. If it ends up being another problem, it's not a bad thing to have a spare you can tie down on the fender inside the engine compartment or throw behind the seat..

 

I don't think the symptoms indicate an ignition module. What I meant about "fail completely" is that the engine either runs or it doesn't when the module fails - either a short-term failure or long-term. The symptom, as I read it, is that the engine will run and pull the truck on the level but not pull a hill or accelerate. That, to me, is a weak spark, and I don't remember seeing the module do that.

 

What I've read is that some testing stations can heat the things up with a hair dryer-type heater.

My local O'Reilly's doesn't have such a testing station.

 

Ah, I see...

I'm going by my own experience on my DD Tempo with the TFI... while it's true that the most easily-recognized (and described) failure is the start-or-no-start scenario, there are certainly other symptoms that come with a dying module or PIP sensor - most notably, the engine will sometimes act like it's misfiring (especially at idle) and can have a marked lack of power at times.

Bad plug wires will also cause a misfire, yes, but how would they cause a heat-related no-start condition?

 

Agree that the hot-start problem doesn't fit with plug wires, rotor, or cap. Maybe the TFI or even the coil? I just haven't heard about the ignition module working partially.

 

Wow I didnt know that all you commented. It never showed up in my email. Ok so this is what ive done.... I put new plugs and wires on her last friday...Didnt run any better or worse. So I took off the ignition module and had it tested at autozone. We tested it about 10 times or so and it kept passing but did get hotter than hell. The guy told me that there was some grease to put on the metal to keep it from doing that. He gave me some and I put her back together. I poulled out of my shop and got on her. She started sputtering instantly. So I got to thinking I never really have to get on it around town so maybe ive had this problem for awhile and just didnt know it. I started thinking fuel filtermay be clogged. So I just got one to put on it and put it on and then I see behind the rail mounted fuel pump was a black canister. Is there another fuel filter inside that??? If so how do I get it out and could that be my whole problem? When I got the truck last year I replaced the tank sending unit with pump and fuel filter. Never even noticed until now that there was another fuel pump and, fuel filter??? Thanks in advance guys