Hi guys. seems my engine holds its RPM too long. If I run it to 4K and ease off the throttle (M6 in neutral) it stays there around 4k till I come to a stop. The car is also having high idle issues. I have read everything about the IAC and issues with larger TB's; I have a 58mm BBK but it has been "fixed" How can these be realted??? I have cleaned my linkage and the inside of the TB excessively. Can this be vacum related?? I will hook up my vaccum guage on Saturday to measure. Also, the car regulary now seems to "fart"when I turn off the ignition. Nothing violent but noticable.
TIA

 

It has to unload the system of it's pressure to come down.
Do you have an unloader(pop off) ya might have to get it tuned to come back to idle.
Unburnt fuel in exhaust causing a pummmp.
Might be the map sensor or IAM not programed right.

 

have you tried adjusting the idle screw on the tb? what about the accelertor cable?

 

pummmp is exactly the sound!!! So un burnt fuel in the exhaust Id like to think its something electrical BC I have not changed anything mechanical. I shouldnt have to adjust the TB idle screw cause it has been set in the past? I dont know about an unloader but I do have an ATI bypass valve.
thanks guys!

 

I have a good idea of what it's doing but there are guys on the board that are a lot smarter than me when it comes to diagnosing computer or tune problems.It could be several thing's
I build um and let my computer guy tune and push the right button's.
Before ya start throwing parts at it maybe somebody like Madwolf or Injuneer or someone that does it for a living,can chime in and put ya on the right track.
The bypass is the unloader.It relieves system pressure when the TB is closed(from reving back to idle) to relieve pressure on the blower.

Have ya talked to ProCharger?

 

So you're running a procharger without a vac/boost gauge? Have you logged the car lately? That's usually the best way to diagnose a problem like that.

 

I just got a guage from a buddy the ther day. where do you guys tap into the intake to hook it up for boost?? Seems every place is taken. I would use the hole on the drivers side but its being used for the bypass valve? I dont have a logger so here I am.......

 

You can T into the line that the bypass valve is using.

 

Thats what I had in mind but I thought it needed to be the secure/threaded hook up. Will do!

 

Nope, just make sure they're good n tight. You may need to clamp them at 15+ PSI though.

 

THanks . Im only running 9lbs now so I shoud be good. Do you know hat I should be reading as far as vaccum goes? Havent searched yet but was jsut wondering.

 

Depends on the heads/cam really.

 

Im not too sure about the heads as they were on there when I bought the ride but lets just say they are some stage 2 heads by morgan motorsports. Cam is a Comp Cams 305H.

 

Probably figure around 16-18 inches of vacuum at idle.

 

Thanks man, very helpful you are.