New IAC, still high idle

[GingerKid]

I put a new IAC in my truck today, and I'm still having a high idle sometimes. Mostly when I'm coming up to a stop. It doesn't seem to matter if I push the clutch in or slip it into neutral, it still want to stick in the 1500-2000 rpm range. Any ideas on what could be causing this?

 

[disciplerocks]

Pull negative battery cable off for 10 minutes to clear the ecu, then run it without using the a/c or defrost for a few days so it can relearn everything.

 

[GingerKid]

I did that and let it idle for about 10 minutes to let it settle. I didn't think it would take a few days though. It seems odd that it does the exact thing the old IAC did too, which is what made me think it was something else.

 

[disciplerocks]

It has to learn idle and all all the fuel trims at all speeds and rpms. I'd do without for a week if you can.

 

[aridranger03]

What brand IAC did you buy? I bought one from advance and mine still acts like yours does.

 

[BRUTUS_T_HOG]

I put a new IAC in my truck today, and I'm still having a high idle sometimes. Mostly when I'm coming up to a stop. It doesn't seem to matter if I push the clutch in or slip it into neutral, it still want to stick in the 1500-2000 rpm range. Any ideas on what could be causing this?

try to unplug the throttle position sensor. a sticky one will make the computer think you still have your foot on the gas

 

[GingerKid]

The IAC I bought was a BWD from Advance. It was the less cheaper of the two options, so I figured it might be a better quality.

How would unplugging the TPS affect engine running? Isn't it kind of necessary?

 

[disciplerocks]

Unplugging it wont help, but it will determine if thats the problem. May be a vacuum leak too. I still say your computer needs to relearn it all. I fought the same issue all winter, not realizing it was my defrost keeping it from learning.

 

[BRUTUS_T_HOG]

The IAC I bought was a BWD from Advance. It was the less cheaper of the two options, so I figured it might be a better quality.

How would unplugging the TPS affect engine running? Isn't it kind of necessary?

because if the TPS is stuck high... say 3% instead of 0%.. the computer will think you have your foot on the pedal and tell the IAC to open more, therefore increasing idle.