hmmm... i just dont know what the heck else it could be...

 

So, you say you aren't pulling any Codes now? You just get 111. And have you been down the IAC road cleaning and checking it? If you are still struggling with idle issues and you aren't getting Codes, you may want to check/clean the IAC valve/solenoid assembly. The easiest way to test a for a dying IAC is to start the truck, warm it to normal op. temp. (about 10 minutes run time). With the truck in park, the air conditioning off, and a steady hand, disconnect the IAC at its connector to the main wiring harness. (Pictures of the IAC on a 5.0 in my gallery). Once disconnected, the IAC should close causing the engine to wind down and die within a few seconds. If it does, but the idle is erratic while the truck is running, try cleaning it with fuel injector or carb cleaner that is safe for coated/sealed throttle bodies and O2 sensors. Take care not to get cleaner into the electronic end of the IAC (the solenoid end). If the engine does not wind down and die, either the IAC is stuck open/failed or the throttle body has been screwed with and will need to be reset to OEM specs.

 

It's the fuel pump, the next time it happens, put a fuel pressure gauge on the valve and take a reading.

Then go to Ford ONLY, and get a new fuel pump. Install or have them do it.

Proceed to DRIVE without a care like you did before.

 

well it wasnt showing codes for like a day now randomly there back. but i unplugged the connecter to the IAC and it didnt do a thing. the engine kept running how it was. so i pulled it off and cleaned it and then turned the truck back on and tried to pull the connector off again and this time it kinda dropped in idle just a little but still never died.

 

That's what I was afraid of. The fact that the engine never fully died with the IAC disconnected is cause for some concern. Even with an IAC that is known to be working properly, disconnecting the electrical connector MUST cause the engine to die. If it doesn't, then either the throttle plates are not fully closing or you have a vacuum leak. Obviously, make certain there are no leaks first (but I think you have already chased those down as I recall). If there are no vacuum leaks, and the condition still exists, make certain the throttle plates are fully closing in the bores. Coking around the plate edges and in the bores and debris in the bores will cause them to not fully seat when they close.

In some cases you will run into a throttle body that has had the TPSS (Throttle Plate Stop Screw) "adjusted" which should never be done. However, some unwitting individuals seem to think this screw is for "idle adjustment". IT IS NOT! "Adjusting" this screw will keep the throttle plates from seating in the bores thus making it impossible for the ECM to control the idle. Often this is done by cut-rate used car lots to "improve" the idle in a vehicle that might not be running just right. Opening stop screw WILL increase idle speed but it will also throw every other operational function of the EEC-IV system out of whack.

If you determine that the stop screw is what is keeping the throttle plates from closing fully, there is a way to reset it. It can be a little tedious, but it will put the idle back to baseline so that troubleshooting any other issues will be easier.

Are you seeing a return of the same Codes?

 

well i have seen that screw but ive NEVER touched it. i even thought that people probably mess with it cause they think its like a carb. but yea i got 332 again. so should i just got pull the air hoses off and see if there seating all the way??

 

Its a classic case of "it couldn't hurt". The thing is that the EVP is the ONLY sensor that tells the ECM that information. You might have a look at the connection and wiring to the EVP as well.

 

yea that would be a good idea. where does the wiring from the evp go to?

 

Rats, I'm not at home and don't have my schematics at work with me. I can look it up and post later unless someone has a Haynes manual and cares to run it down in the meantime.

 

I got a Chilton but i doubt it would help It only goes from 76 fords to 86....

 

i think i have a chiltons for it. let me do some reading and ill let you know what i come up wit. by the way i just wanna say thanks! you have helped me alot with this!