Hanging RPM's

[RysRed96GT]

Sometimes when I'm driving for a while and the car gets warmed up, when I let off the gas and put it in neutral (or clutch in), the rpm's hang between 1500 and 2000 rpm. sometimes if I flip the throttle a few times it'll go back down.

Any idea what could cause this? Thanks

 

[forpit2000gt]

Have you had your car tuned? I have had hanging and fluttering rpm problems evertime I added or changed something on th eplenum. I removed the 1/2 inch spacer and it cleared before I went with the C& L unit.

 

[timeless2]

IAC mod....

 

[RysRed96GT]

nothing has changed in my setup. the rpm's dont fluctuate. only after the car is pretty warmed up it will do it.

and if the iac mod you're referring to is the one where you place the gasket with the smaller diameter hole on there...then no.

 

[jrc_03_gt]

make sure egr is tight against the plenum and maybe replace the gasket. It worked for me.

 

[RysRed96GT]

bump