The EEC was in fact the cause of the problem I was having. The truck is running great again!








After tracing wires from the injector to the computer - I have determined that the EEC is not driving the injector.

What do I need to do to get a new computer - then get it programmed?

 

Identify your vehicle by year, engine, and transmission.

There are several reasons why the PCM may not be firing the injectors, all of them normal. PATS issues and TPS problems come immediately to mind.

Start over by explaining what is going on and what you have done to properly diagnose the fault. You very likely do not need a computer. While they occasionally fail, most that get replaced are not the real problem anyway.

Otherwise, you will need to take it to a dealer to have the PCM programmed to anything other than the default programming.

Steve

 

Sorry to be so vague. We did quite extensive troubleshooting to arrive at the conclusion.

I bought the truck with 99K miles on it. 1999 f150 2wd 5.4 triton

It has always had a weird miss - I always attribuited it to drivetrain imbalance since I only noticed it in the rear view mirror while driving.

The other day I got in and started it and it started idleing like a hot rod .

I drove it a little and it did not get better ( I did check for the blown out spark plug) That wasn't the problem.

After a little more driving the Check Engine Light came on.

So I took it to AutoZone and had them read the codes. P0301 cylinder 1 missfire.

After reading quite a few posts about coils going bad - I switched out the coil with a new one. Problem didn't go away.

Next replaced the fuel injector and spark plug (resetting the computer both times) No Change.

I took it to a good friends shop and he put a tester on the fuel injector wiring and it was not firing the injector (just the #1).

He said sometimes the wires break - We got out the wiring diagram and checked the wire all the way to the EEC and it was good.

My logic says that a TPS will not cause a single cylinder to not get fuel.

I have a friend at the dealership getting a computer for me. It seems like they are having a heck of a time finding one. Isn't this computer in EVERY Ford from like 1996 on?

DO I understand correctly that all of the EEC-V computers are identical with the difference being that that have a different programming?

Thanks!

 

That fills in the blanks.

Provided there is power to the #1 injector, then I'll certainly agree that the PCM is very likely the problem. Probably a blown injector driver.

The parts specialist at your dealer is the best person to answer the question about the PCMs. I haven't run into this before...

Steve

 

Thanks for the reply - We did make sure that there was power to the injector.

 

The PCM supplies a ground to the injector. If you can operate the injector from the PCM plug that should all but prove the PCM is not supplying the ground.
A meter on the injector would also show the same thing while the motor is running and include the PCM.
To be sure the coil is being pulsed for spark use a good clip on light around any cable at the plug coil and it should pulse the light.
Just a thought. The table for that cylinder in PCM program might be in a garbage condition. Try rebooting the PCM by power removal.
None of this cost money, to be sure, before buying the new PCM.

 

If you determine that it is the PCM, before you buy a new one, check around for someone that knows a thing or two about electronics. (A Ham radio geek would be a good start. I am one so don't go off on me about the geek part....) If they can determine that it is just a driver that is bad in the PCM, it could be fixed for a buck or two, and maybe a case of beer.

 

So....Explain something to me. If I order a EEC for Ford doesn't it seem logical that it would come programmed. Not so much.

I thought I remembered that the dealers have the ability to program the EEC with out the car. Is that true?

 

solved

 

Glad it's fixed.

When you get a chance, fill us in on what it took to get the correct EEC for your truck?

Were you able to simply purchase it and get it to plug and play or were special measures required?

Steve

 

OK, Here's the details as I know them.

I gave my friend the VIN so that ford could get me the correct computer.

The one I recieved had a part # with the last digit incremented. Like a C instead of a B.

I questioned this and found out that this was a 'upgraded version' of the original. Apparently they fixed a bug.

I used to have an '88 corvette and the security is done in a seperate module.
So...I assumed that it was still done that way and the computer would come pre programmed.(not so much)

The guy that got the EEC for me (dealer price) wasn't a techie and didn't know anyone in the service dept. so I solicited some help from a different friend.

I had to put the old EEC back in and drive to the dealership on 7 cylinders. (ran like a hot rod with no power)

I took the truck down and left it at the dealer over night so that they could work on it at their leisure the next day.

So about 10 am I get this call from my friend - he says they need a second key or they can not program the EEC. So I frantically call my son and have him run the other key down.

The truck runs great now.