The EEC will look well inside when it is bad.
What goes bad with a EEC (PCM) computer over time is the caps.
Here is a url on how to replace them. http://www.tmo.com/howto/ecu1g/caps.htm

The best way to find out for sure on the pick-up inside the distributor is to look at the pulse train from it with an oscilloscope or replace it.

 

I will reattach the grounds as they were. It appeared that they were factory in that location.

I'm going to look over the computer a bit closer and then reattach it.

Without Oscopes etc. I am shooting in the dark to some degree, plus someone has been playing inside the truck if you catch my meaning.

Coil diagnosis next.

I really feel that the issue is definately ignition related.

Thanks for your help, ROB

 

Current update:

I spent a bit of time after work and did the whole Hayne's thing to try and find an issue in the ignition system.

All the voltages were appropriate with no appreciable drops to the coil and all the pins on the TFI.

The coil resistances etc. were where they needed to be.

There is a couple of things left to check.

I called the local Ford dealer and then spoke to another knowledgeable Ford guy and they both told me the same thing.

The TFI module is prone, make that very prone to failure.

I realize that this is very old news to most of you. I was unsure if I should buy one or not because it did bench test fine on resistances. I did not go out and have it tested, which I will do prior to purchassing one.

Ideas, opinions?

It is running fair at idle, not good above that even cold now. This is different than a few days ago where it ran good until about ten minutes. It is definately getting worse.

Thanks for your help, ROB

 

I did tell you that the TFI module was the prime candidate in my first post to you.
I would never go by anything a Hayne's manual said anyway, they just copied what they wanted to out of the Ford Shop Manuals and tried to make the information cover lot of years.

 

Hey Subford, I do believe you did!

One of the biggest challenges that I have faced is the lack of information here and I agree that something other than haynes would be better like a fsm.

I guess it was just too obvious to notice, plus it has not "just died". However with more research, the fact that it is getting worse, and it runs funky when it gets warm tells me that it is the likely suspect.

I'm quite mechanically inclined, you know the build 4x4's from scratch thing, but this has been good for alot of head scratching........

I guess I didn't want to run out and buy unneeded parts on a whim. I had a 5.0 years ago and I saw the same thing when I was looking to repair it.......people buying every sensor known only to may to find a bad ground.

Would you purchase the PIP for the distributor? I was also thinking about the EEC relay , or do they go bad? Would a faulty relay cause the no codes issue?

Thanks for all of your help, particularly you Subford. I'll keep you posted.

ROB

 

Quote:

Originally Posted by toyotajeep

Would you purchase the PIP for the distributor?

No, not until I changed out the TFI, even if your TFI is good, a spare in the glove box with a wrench for it is a lifesaver if you are out somewhere.

Also the PIP in the distributor is not an easy change, you have to pull out the distributor and take the shaft out of it with a press. If the sensor is bad just replace the distributor.

Quote:

Originally Posted by toyotajeep

I was also thinking about the EEC relay , or do they go bad?

Yes they can but if it is bad, the engine will not run (the injectors will not fire) but you would have base timing spark, the same as if you had pulled out the SPOUT.

Quote:

Originally Posted by toyotajeep

Would a faulty relay cause the no codes issue?

Yes but again no CEL (MIL) and the engine would not start.

 

OK good news.

It was the PIP in the distributor. I replaced the TFI first thing this morning, even though the store said it tested ok. They had an ancient computer that would hardly run the test so I was unsure about the results.

I purchased a PIP sensor and a TFI. When the TFI made zero differance I did the next thing and pulled the distributor again and replaced the PIP.

One of my kids lost the hold down bolt, but we had the distributor out and back in within an hour, including looking for stuff so I figured that was ok.

It seems to run about 85% or so. Not perfect, but seeing as how the truck has sat for so long and the timing is not set yet I am very happy.

When I had the distributor out earlier the PIP didn't "look right" but I live a long ways from the parts store so I just lived with it since it was a hunch anyways.

I could go on with more happiness, but let's just say that it is a good feeling.

Now I have a few more hours of misc. stuff to clean up and then we can put it on the road and drive for awhile. I think alot of the small stuff will take care of itself with the driveability issues and all once it gets some good gas and what not.

Thanks to all, it would have been very difficult to have done this without your help.

ROB