Who has ran a LS1 throttle body on a custom intake manifold and had idling issues and issues with the engine revving down really slow? Im trying to figure out what else to do to make it idle where it should, and rev down like normal. This is on an ecotec with custom intake manifold. Im guessing I need to block off something else in order for it to act right. The little hole in the butterfly has been closed off, and the port on the opposite side of the IAC has been blocked off... What has everyone else done?

i believe the little hole in the butterfly is there to make it idle right.....unplug it..

correct you need the hole open, in some applications u need to bore the hole bigger for bigger lift cams if applicable

well if the hole is open, there will be even more air going through. then the idle will be even higher. do I need to block off everything except the butterfly, then open that hole up for propped flow. cause right now it's not acting like it should cause it's still getting way too much air

Ive run two diffrent custom manifolds both with ls1 throttle body and have never blocked anything off. Car idles perfect. Maybe tps is bad? Leak at throttle body gasket?

i blame it being barrs car because he is a fag..

we will prolly have the same problem with yours too Paul.

Ben D(Silver J on 1Nines) wrote:we will prolly have the same problem with yours too Paul.

ya i have bad luck i expect it..

Now that think of it i took off my intake and put it on a bone stock car and it idles perfect i wonder why you guys are having problems.