High idle

[Sweet6]

I helped a friend change his intake manifold and throttle body out and now the car idles around 1300 RPMS and that is with backing out the idle screw all the way back. I checked all of the vacuum lines and they check out. Let me know if you have any ideas.

Thanks

 

[Tweeked6]

You have an air leak sir.

 

[Sweet6]

I know can't find it lol

 

[Tweeked6]

Hint hint........ It may be the parts you changed. Lol

 

[Sweet6]

Changed every part lol

 

[earlbrown]

and that's not an 'idle screw' it's a 'minimum air 'screw.

 

[Buick Mark]

IAC motor

 

[GetOwnedVette]

Gasket on the throttle body and plenum good?

 

[Sweet6]

I checked those I think they are good But I was going to check those again.

 

[Sweet6]

I have done this a few times. I am not sure why Iam having a problem now. I posted up just in case I am missing something that I am not thinking about.

 

[John Larkin]

Spray carb cleaner with the straw around the areas where gaskets are (or WD40, ether will work for this). When the carb cleaner momentarily seals the gap, the idle will drop. Then you will find the air leak. Could easily be a manifold gasket not sealing to the head.

 

[Sweet6]

Just put a new intake gasket on. I am going to relook at all of the hoses. and plenum and TB gaskets

 

[aminga]

Any Scan tool data to look at?

 

[Sweet6]

yep I looked at all of that too. But I know it is a vacuum leak. TPS, IAC, and the rest of the numbers are good. I am just going to relook at the hoses and upper plenum and TB gaskets.

 

[Sweet6]

IAC was stuck wide open