IAC not closing idling @ 2500 rpms
09-23-2013, 07:42 PM
#1
IAC not closing idling @ 2500 rpms Has anyone experienced this issue after a tune. My IAC is staying open at idle. Tuner advised this happened to him while he was tuning my car we got a new IAC problem went away. I got my car about a week ago I brought it to temperature, idled correctly for about 15 mins. Took it out for a drive went wot and thats when it started idling at 2500 rpms. I bought a new iac but it is still hanging idle at 2500 rpms. Any help greatly appreciated.
Last edited by Tirefire; 09-23-2013 at 07:59 PM.
09-25-2013, 12:25 PM
#10
what is commanded and what is current?
bend your throttle farther shut?
you should have 40-68 steps for a cammed warmed up car idling. if its at 0 it is bottomed out and that is something sticking open, vac leak, or bad IAC controller or motor.
also i have had this work when other things were funny
--------------------------
You need to relearn your IAC, it is reading 0.
They these steps.
IAC Relearn Procedure
If you are having idle issue you may need to reset your Idle Air Control (IAC) and
TPS, do this before you start drilling holes in your throttle body (TB) blade. I have
used this procedure on some huge cammed cars and it worked.
1) Monitor your IAC, Idle Speed, throttle position voltage and your throttle position %.
2) With the key in the ON position, adjust your TB set screw until your throttle position
is 2%.
3) Turn your key to the OFF position.
4) Unplug your Throttle Position Sensor (TPS) and IAC.
5) Turn your key to the ON position for a few seconds, and then OFF again.
6) Plug in the TPS and IAC and then turn your key to the ON position and restart
logging. Your throttle position will now be reset to 0 degrees and about .45-.55 volts.
7) Start your engine, your IAC should be 40-60 for a cammed engine.
if you are not at your desired IAC position redo the above procedures in smaller
increments.
------------------
bend your throttle farther shut?
you should have 40-68 steps for a cammed warmed up car idling. if its at 0 it is bottomed out and that is something sticking open, vac leak, or bad IAC controller or motor.
also i have had this work when other things were funny
--------------------------
You need to relearn your IAC, it is reading 0.
They these steps.
IAC Relearn Procedure
If you are having idle issue you may need to reset your Idle Air Control (IAC) and
TPS, do this before you start drilling holes in your throttle body (TB) blade. I have
used this procedure on some huge cammed cars and it worked.
1) Monitor your IAC, Idle Speed, throttle position voltage and your throttle position %.
2) With the key in the ON position, adjust your TB set screw until your throttle position
is 2%.
3) Turn your key to the OFF position.
4) Unplug your Throttle Position Sensor (TPS) and IAC.
5) Turn your key to the ON position for a few seconds, and then OFF again.
6) Plug in the TPS and IAC and then turn your key to the ON position and restart
logging. Your throttle position will now be reset to 0 degrees and about .45-.55 volts.
7) Start your engine, your IAC should be 40-60 for a cammed engine.
if you are not at your desired IAC position redo the above procedures in smaller
increments.
------------------
09-25-2013, 08:54 PM
#11
Denmah my IAC are at zero at idle according to hp tunners scanner. I did the above and did not work IAC stayed at zero. It seems like for the first minute that its warming up its at 1100 rpms but as soon as it warms up it creeps up to 2500 rpms and stays there then after a minute it drops and hunts for idle then jumps back up to 2500 rpms. I also noticed when driving it the other day it only wanted to be at 2500 rpms I had to control the rpms by down shift to 4th gear. This sucks....
09-26-2013, 08:05 AM
#15
open vcm scanner
key car on, not running
connect vcm scanner
click vcm tools next to the check engine light,
pull throttle body off, command higher and lower idle, see if IAC is moving in and out
key car on, not running
connect vcm scanner
click vcm tools next to the check engine light,
pull throttle body off, command higher and lower idle, see if IAC is moving in and out
09-26-2013, 08:51 AM
#16
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Down load the tune before your tuner messed with it, if it wasn't doing this when you took it to him and see if it takes care of it. That would be interesting to know. Quick and easy check.
09-26-2013, 12:53 PM
#17
Ok got hp tuners and commanded my IAC by zeroing it out first then hitting the step tab and I could feel the motor activate but the plunger would not move. I then max it out at 127 and hit the step tab and again I could feel the motor inside activating but the plunger would not move. The thing is I did this with two IAC sensors one I bought the other day and the one I bought my tuner when the car was with him? Can anyone tell me what this means.. Thanks
09-26-2013, 01:01 PM
#18
Ok sorry I also commanded higher and lower idle hit rpm tab and nothing no motor activating or nothing??? I also played with the step counts while moving the rpm up and down and nothing. RPM tab when pressed no activation, Step tab when pressed motor activated but no movement at the plunger.. Anyone with any ideas..
09-26-2013, 02:25 PM
#20
That's probably correct. There's a tab in there where you can specify what you want the IAC motor to go to when you shut off/turn on. It helps with starting the car, think of it like in the old days when you had to 'give it a little gas'.
Once you actually start the car, the IAC motor / counts should go down fairly quickly as the car warms up.
It sounds like you have a vacuum leak somewhere or the throttle body isn't closing completely.
Once you actually start the car, the IAC motor / counts should go down fairly quickly as the car warms up.
It sounds like you have a vacuum leak somewhere or the throttle body isn't closing completely.