high idle on 1996 ford windstar

[hottey2go4]

I have cleaned the egr have replaced the maf the iac the spark plugs the wires and the throttle cable this thing is still idling high when you hit the gas piddle the rpms go to 2 and I have taken to the shop they have no idea. When you take the throttle sensor off idles fine so we changed the throttle sensor and it idles high as long as its on. Does anyone have any ideas what to do?

[wiswind]

I would try cleaning the IAC (Idle Air Control).
Spray some WD-40 or SeaFoam inside it to clean and lubricate the threads of the screw in there.

The IAC takes over the control of the air into the engine (and the idle speed) when your foot is not on the accelerator. The PCM senses the position of the accelerator through the Trottle Position Sensor (TPS) and controles the idle speed by opening and closing the IAC.

The IAC is located on top of the upper intake manifold.....next to the throttle body. It is held in place by 2 small bolts....and has an electrical connection. It has a little motor inside....that turns the screw.....and opens / closes the airflow into the engine. You remove it.....and look inside....and you will see threads on the screw.

It sounds like when you disconnect the TPS, the PCM then flags the TPS as being open....and ignores that value. When the TPS is connected.....the PCM is trying to control the IAC....but it is not responding.
You can also replace the IAC, if cleaning does not help.

The only other thing that I can think of....is to make sure that there is not some kind of vaccum leak....but your CEL should light up if you had that much of a leak.
Also, make sure that the throttle linkage is not hanging up somehow...and not permitting the throttle to go all the way closed when you foot is not on the accelerator.

[hottey2go4]

I had put a new IAC on it but I will try looking at the throttle linkage. Well now it said I had a dead cell on number 4 then all of sudden today cell 4 came back to life. We have went over the vacumm hoses and nothing was un done on it. So if anyone else has any suggestions please tell me this thing is so puzzling a first when I got it back from haveing a new motor put in it it would die everytime you would stop we cleaned the egr and the thing stopped doing it then all of a sudden driving dow the road the thing idled real high and now everytime you start it it goes right up to 2 and sticks there.

[busboy4]

Hi
I had an '87 Tempo with high idle. It was simply the PCV valve. I am not suggesting this will definitely fix your problem, but you have checked all the "likely suspects".

Good luck.