Rpm Goes Down At A Stop

[cashflow50]

2003 GMC Yukon 4.8L

 

What is wrong when at a stop, the RPM goes DOWN couple ticks then go up to its normal position at 700? My brother in-law has a GMC truck with the same type of engine and his goes UP a couple of ticks then down to 700. Whats up with that? Its reverse and it seems odd. Please chime in experts. Thanks.

[Stevens03]

Well, I'd start with the basics. Clean the MAF sensor and throttle body then replace the fuel filter and air filter if they've not been done in a while. Report back.

[cashflow50]

Well, I'd start with the basics. Clean the MAF sensor and throttle body then replace the fuel filter and air filter if they've not been done in a while. Report back.

 

I know this sounds nub, but what do I use to clean the MAF sensor and throttle body? Also I have a K/N drop in filter, so thats good to go.

[Stevens03]

They make MAF cleaner found at most auto stores or you can use a good electrical contact cleaner. Just don't touch the little diodes with your fingers. The throttle body and blade can be cleaned with the same stuff really. If there's any "coking" on the blade or opening, it can cause idle issues.

 

Be careful not to over oil the filter too.

[cashflow50]

They make MAF cleaner found at most auto stores or you can use a good electrical contact cleaner. Just don't touch the little diodes with your fingers. The throttle body and blade can be cleaned with the same stuff really. If there's any "coking" on the blade or opening, it can cause idle issues.

 

Be careful not to over oil the filter too.

 

Stevens11..you've got mail.