Ford Repair Questions? Ask a Mechanic for Answers ASAP
Thanks for the question.
The only thing I didn't see on your list above was the IAC (idle air control) solenoid. This controls all idle functions. You should have a high idle at startup and this controls the air flow to the engine.
I suggest that you remove it and clean it with a small brush like a toothbrush and some good carbon cleaner and then reinstall and unplug the battery for 15 minutes to reset the computer and retest.
It is located on the side of the throttlebody.
Sure, no problem just come back to this same post.
With the engine idling at normal temp, unplug the IAC and let me know what the engine does please?
Ok, sounds like you might have a bad IAC. First make sure with the key in the run position that you have 12v at the red wire. If you do then replace the IAC and unplug the battery again to reset the computer and let me know how it turns out.
Yes, key on engine off just for safety sake.
Yes, disconnect the battery for 15 minutes this will reset the computer to factory default.
The reason it clears up after it warms up, is kind of misleading what is going on. When the engine is warm it doesn't need a high idle any longer. With a cold engine it needs a high idle or it will do what yours is doing. By you unplugging the IAC and it making no difference, the IAC is doing nothing, it is dead.
The sensor I think you are describing is the IAT (inlet air temp) and yes this can cause issues and might not set a code, so go ahead and replace that if it looks bad.
The IAC when unplugged during idle should almost cause the engine to stall. So either the IAC is not working properly or someone has messed with the throttlebody idle screw and jacked up the throttle plates. So you can try to turn the set screw for the throttle plates back so the throttle plates close more so the IAC can do the job. If after that you unplug the IAC and the engine doesn't change and almost stall the IAC is bad and will need to be replaced. The IAC is part electrical and part mechanical. I think the mechanical part has failed.
Just back the screw down 1/2 turn at a time. This screw was never meant to be messed with it was suppose to be set from the factory.
I will most likely be online then.
Earlier in the post you said the fuel pressure was good, what is the actual fuel pressure?
And there is still no codes?