Is there a way to determine this for sure? I've been having a problem recently where the car will idle very very high (at about 2000RPM) and doesn't want to kickdown. It will eventually, but it's not consistent.

I hooked up the scanner to it and the IAC steps last night were at about 100 with the target steps supposed to be at 0. I have already removed the IAC and it was completely clean, so it's not a matter of it being gummed up. And the sensor is only about 10,000kms or less old. (replaced last year).

I unplugged the IAC while the engine is running and the idle speed did not change. So I hooked it up and again, it did not change. Does this mean the little motor is toast? I don't want to replace it if I'm not sure.

What else would cause a high idle?

 

Rocker,
unplugging the IAC while running won't change the idle anyway since it just leaves the pintle exactly where it is. Plugging it back in will only make a diff once the car is restarted. Just FYI my target steps and actual are never the same. Did you try setting the min. idle?

 

every so often my idle likes to stick so i pull off my TB and lube the throttle blade shaft. and all is normal again.
it does this due to cleanings of the TB on my car.

 

Thanks Jeff...I thought it might go back to a parked position or something, but I wasn't sure. When the car is running right is actually seems to match the target IAC steps fairly well. Strange how you note yours to be different. Since it does idle at the proper RPM sometimes (just not all the time), I didn't want to mess with the min. idle screw.

Richard, the TB blades appear to be moving freely. They don't seem to be sticky at all.

 

i noticed the same on my 86 305 tpi at the lights i see the tach drop to 200 and then pick up again , like its ready to stall , just started doing this since last tank of gas
anyone

 

you wont feel it being sticky ,it only shows when running for some reason. if ya flip the blades it will feel normal.
after each TB cleaning i put a lil lube and it dosent happen. after a few months it starts getting "sticky" so i lube it and all is good.
next time it idles up park it while its idling up, pop the hood and push the arm towards the stop .
thats what i did.
then again the IAC may be going. is just a sugguestion to diagnose so ya dont start throwing part at it.

 

Thanks Richard...I tried pushing the throttle arm back, but it was already flush up against the stop (as far as it would go). OUt of curiousity though, what kinda lube did you use?

 

i use silicone spray or WD-40.
the silicone seems to stick around longer.

 

Cool...I've got both sitting at home. I'll try that out the next time I got the snokel off.

 

i usually pull my TB off to do this as i turn it on its side to let the fluid get down into the shaft area. im sure to wipe down the excess after.

 

Okay cool, I'll keep that in mind.

 

how do you go about checking the IAC valve? do you have to have that tester made for it, or can you use a meter??? Im thinking that maybe the cause of my rough idle......since Ive checked/replaced/cleaned everything else.....

 

just curious, did u get your rpm's to go down cuz my is doing the same thing, cuz i also started to think i was my IAC but im getting code 15, 21, 36, and 42 and its idling at 2000 aswell