i've done a swap to a 2001 ls1 in my silverado and the idle is rough on it. it'll drop and raise right around 500 rpms and sometimes die. i have a SES light and that is for intermittent TPS, but we've replaced that. we've also sent the computer back with a log, but we haven't recieved it yet.

any ideas?

 

no ideas?

 

hmmm....i guess since i'm not asking about a cam, i'm on my own....

 

Is the LS1 engine all stock? If you got it used, someone could have put a cam in it, changed the stock PCM tunning, changed the MAF, etc. Check for vacuum leaks as well. Are the TB hose clamps tight? Have fresh gasoline, how do the plugs look? Stuff like that.

 

Check the intake manifold bolts - make sure they're torqued down to spec.

 

it's mostly stock...just exhaust, headers, intake, and tuning. How do i check for vacuum leaks?

 

is there another place i should call/post to ask these questions?