99 suburban idling high

[Pontihog]

Hi,

My 99 burb has been idling high as I slow down lately. After coming to a full stop, I can throw it in neutral and the tach is at 1500rpm and then comes down to 500-600 after about five seconds. I notice the rpm staying higher as I am coasting towards red lights or stops.

No check engine light.

Any help will be appreciated.

Thanks

Ponti

[j cAT]

Originally Posted by Pontihog

Hi,

My 99 burb has been idling high as I slow down lately. After coming to a full stop, I can throw it in neutral and the tach is at 1500rpm and then comes down to 500-600 after about five seconds. I notice the rpm staying higher as I am coasting towards red lights or stops.

No check engine light.

Any help will be appreciated.

Thanks

Ponti

this is a common problem...the IAC and throttle body need cleaning.....with a tooth brush and throttle body cleaner [NO CARB CLEANER]
remove the carbon build up...since you will be removing the air ducting this would also be a good time to clean the MAF sensor with CRC MAF cleaner...I'm sure you will find the engine will run better....the IAC is held in place by 2 screws at the side of the throttle body...do not try to rotate the IAC just clean it gently with the soft brush and cleaner....spray into the hole also....inside is a seat make sure its clean...

[Pontihog]

Thanks,

That took care of the problem.

Ponti