Weird Idle Problem

[95GTeee]

I recently installed a FMS 65mm throttle body. I adjusted the idle stop and air idle control - all is well. All cables are adjusted properly and the spring snaps back the TB plate. New gasket and all plugs are seated correctly. The TB works well ... BUT ... after giving it gas and letting off on the throttle, the engine kinda "hangs" and the engine RPMs drop slowly. I counted and it takes about 7.5 seconds for it to return to normal idle. Hangs around 1200 RPMs mostly, then finally drops suddenly to 650 or so after those 7 seconds. The car doesn't accelerate, but doesn't decelerate either.

WHY??? Sensors??

 

[JJ95GTID]

Might need to reteach ECU. Disconnect (+) terminal on battery and open driver's door to drain any left over power. Then reconnect and go for a drive.

 

[95GTeee]

Ooops ... yea, forgot to add that. I disconnected the battery for over half an hour with the hood opened (hood light). I was hoping that would help - but no! Thanks for the advice though!

 

[mytight95]

i would adjust the IAC valve a little more(adjust to where it gets less airflow) is it doing this as you come to a stop or what?

 

[Redsnk95]

Yep...IAC valve is too high...unplug the sensor and then lower the idle a little.

Troy

 

[95GTeee]

When idleing ... its perfect - not too high, not too low. It's whenever I press the gas pedal. Doesnt matter if I am moving, or stopped, or at 3000 RPMs, or 900 RPMs. It's ANY time I release the gas pedal, even if I just sit and rev the engine - the idle just kinda 'hangs' and SLOWLY falls back to normal idle (7.5 seconds). If I adjust the IAC any lower, I will be idleing at around 500 RPMs .... however ... I never unplugged the sensor when I made the adjustments - do I need to have it unplugged before changing it? Should the engine be running or off?? Thanks guys!

 

[smokediver27]

Ive experienced the hanging idle as well when I opened my IAC to far, I had to go back down to the lower idle. From what I understand, a chip or tweecer is the best way to change idle, from what Ive found , trying to change it with either screw just pisses of my computer.

 

[95GTeee]

I am gonna attempt to swap out the IAC from the 60mm TB to the 65mm TB ... the old one was working fine - who knows!! I'll take a look at it tonight.