I have been trying to fix my high idle problem for months now, but i have been reluctant to buy a new idle air control for $50, so i have been experimenting with my car trying to fix the idle problem, and there are no vaccuum leaks. i have done eveything else besides replace the IAC, to test the IAC, I removed the IAC assembly and plugged the holes leading into the throttle body, from the current idle of 1500rpm, it lowered to the normal 700. Is this a sure sign that the IAC is causing the problem? Even when i unplug the wires to the IAC the idle remains about the same, but drops only like 20-30rpm. I would be extremely appreciative if anybody would please help. What i was wondering was whether or not the IAC opens at idle, even when no accessories are running like a/c, headlights, blowerfan, coolingfan, etc.
Question about idle air control and throttle body
- Thread starter darkarrow
- Start date
slowhatch82
Founding Member
have you tried cleaning the IAC? take it off, and spray carb cleaner in there, carbon builds up inside there...
goodluck!
Chris
goodluck!
Chris
i have cleaned the IAC with carb cleaner and i used a wirebrush. the IAC is perfectly clean, literally. it is polished internally, and made certain the valve was not sticking, yet still idle problems. i have also looked everywhere for a leak in the vaccuum system, still no resolve. i apperciate your advice though.
heres what you do
disconnect the iac motor and set your base idle with the adjustment screw, get the idle down to about 500-600 rpm. get it running slow and about to die out and then set it up a little bit. turn the car off and set the screw in a little bit in so the butterfly valve doesnt catch on the aluminum. after you do that disconnect your battery for 10 minutes, this resets your pcm. after 10 minutes connect the battery and the iac motor. let the car run for 2 minutes at idle. dont turn on anything else like radio or rear defroster. after 2 minutes drive it around for 10 mintues, this process resets and relearns the stratagies for the idle.
also if there is a little block in between the iac motor and the throttle body that is an quick ford fix. you might want to remove it. what it was is a controlled vacuum leak that you can set with two screws. some have them and some dont
disconnect the iac motor and set your base idle with the adjustment screw, get the idle down to about 500-600 rpm. get it running slow and about to die out and then set it up a little bit. turn the car off and set the screw in a little bit in so the butterfly valve doesnt catch on the aluminum. after you do that disconnect your battery for 10 minutes, this resets your pcm. after 10 minutes connect the battery and the iac motor. let the car run for 2 minutes at idle. dont turn on anything else like radio or rear defroster. after 2 minutes drive it around for 10 mintues, this process resets and relearns the stratagies for the idle.
also if there is a little block in between the iac motor and the throttle body that is an quick ford fix. you might want to remove it. what it was is a controlled vacuum leak that you can set with two screws. some have them and some dont
to clarify, when he said "a little block" in the last paragraph, he means a metal plate (i originally thought of an impediment when i read block).mustang64up said:
and yeah, if the car dies when the IAC is unplugged, a common fix is to set the idle with the IAC unplugged (so the IAC wont be vital to warm idle, but only for cold idle and load compensation).
good luck.
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