IAC tests good, yet doesnt move. Idle is fubar
05-01-2010, 12:33 AM
#1
IAC tests good, yet doesnt move. Idle is fubar Okay, to make a long story short. No vacuum leaks, no DTC's, heated O2's with long tubes. Engine ran sweet about three weeks ago. Came back from TAD, now it wont idle below 1400 rpm. Turn AC on it goes down. O2's are working fine using my scan tool.
I sprayed bubbly water over all hoses etc and nothing changed. No exhaust leaks. Cleaned the living heck out of the throttle body and IAC housing.
IAC is very clean, and I didnt clean it as it is a couple years old.
I checked the pins for resistance and the IAC is within specs. I also connected it and put it in a bag and turned the key on, NOTHINg, it didnt move at all. So, being a 93, I pulled the spring down and turned the IAC out and in for several test to see if it would move. Nothing.
I then put it back in the throttle body at 1", 1 1/8", and 1 3/16 " without the connector and the idle changed, got higher as I went shorter and at 1 3/16 it was at 1100. (My engine chip is set for 850, and I also tried three different older tunes that worked prior to all this and the idle never changed).
So, I reconnected IAC connector, started it up and no change, turned ac on and it brought it down 200rpm.
Took it out and it didnt change length.
Should it change length when it was out and connected and I turn the key on? Should it have changed length within the engine when running and ac turned on?
Can an IAC be bad, yet show its resistance reading being good?
I sprayed bubbly water over all hoses etc and nothing changed. No exhaust leaks. Cleaned the living heck out of the throttle body and IAC housing.
IAC is very clean, and I didnt clean it as it is a couple years old.
I checked the pins for resistance and the IAC is within specs. I also connected it and put it in a bag and turned the key on, NOTHINg, it didnt move at all. So, being a 93, I pulled the spring down and turned the IAC out and in for several test to see if it would move. Nothing.
I then put it back in the throttle body at 1", 1 1/8", and 1 3/16 " without the connector and the idle changed, got higher as I went shorter and at 1 3/16 it was at 1100. (My engine chip is set for 850, and I also tried three different older tunes that worked prior to all this and the idle never changed).
So, I reconnected IAC connector, started it up and no change, turned ac on and it brought it down 200rpm.
Took it out and it didnt change length.
Should it change length when it was out and connected and I turn the key on? Should it have changed length within the engine when running and ac turned on?
Can an IAC be bad, yet show its resistance reading being good?
