Odd Idle Issue

[Wildfire007]

I'm just wondering if anyone else has had the same issue as me and what the problem was.

When I'm accelerating hard and then let off suddenly and put the car into neutral the idle drops to almost 200 rpms, barely keeping from dieing. It doesn't always do this so I'm not sure what the problem is.

 

[Turbo Habanero]

Ya mine does the same It's a vaccum issue or unmetered air..

Mine does not do so much anymore as I've gone thru nearly every vaccum source and made sure it is connected and in spec. I'm also running a vented bov.

Another thing is make sure your Tps is in spec.

 

[hvyman]

Also could be isc valve.

 

[Wildfire007]

My first suspicion was a vacuum problem as well.

 

[shipkiller]

what should be the vacuum reading at idle?
-20 on a aftermarket boost gauge?

 

[Wildfire007]

I know my stock boost gauge doesn't work. It goes to 0 when I turn my car on and then will not rise or fall afterward.