My car is a vortech supercharged ls2. I have the Hobbs switch, kb boost a pump, and boost gauge running off a vacuum distribution block.

Before putting the super charger on, I noticed that the car would like to bog down during braking. would drop past idle, down to about 400 rpm, then bounce back up to 700.

The car has a tendency to do that, now and it's getting worse. especially when the car has sat over night and is cold. I'll start it up and back out of the garage and the car will want to bog down and almost die. it actually did die the other day.

Well I went to the gas station the other day and a guy came up and asked if my car has been ideling like that. cause it kinda bogged a bit when pulling in. he said that it sounds like the idle control valve is faulty, or i have a vacuum leak. He happened to be a mechanic with a good ear and a love for corvettes....

SO anyway, my question is. i have been trying to find out exactly how to fix the issue. on advanced autoparts and ebay they have what looks like to be a small part that goes on the side of the throttle body. thing runs about 25 bucks..and didn't know if it's the right part or not. any help on explaining exactly what I need to do to replace/fix the issue would be nice till then I'll check my vacuum hoses, and tighten up anything on the distribution block.

 

there no idle air valve on a LS engine

 

Just for clarification... no LS with an electronic throttle body will have a IAC valve. But you will not find one in a C5 or C6.

 

that's what I read..but when I looked up an ls2 with Idle air controller. google came up with picks of I guess a gto or something ls2 with an aftermarket throttle body...

thanks for the clarification guys!

Love this forum.

 

short of a mechanical problem, you can fix the idle issue in the tune

 

outside of something loose. clean the MASS carefully and t-body, if that doesn't work, you will need to tweak the tune. add some more air at idle.