as the title says, we just recently installed a str pro drag manifold up to a ls head, stock throttle body and map sensor, everything is plugged up and looks fine, when we start it up, its fine, and then when the temp gauge moves up and warms up, the car starts to jump from like 800rpm to like 2000 rpm, if its gassed to like 3k, then it doesn't jump, but the idle is mad wierd, the only thing we can think of is the iacv, but we didn't do anything to mess it up? anyone install one of these? and also on the bottom it has a hole stickin out, looks like its for a vacuum tube, but 2 other people said to leave it open and leave it alone? any ideas?? thanks fellas

 

if that hole is not plugged it surges like that so use your finger and plug it and sees what happens.

 

from what you describe it seems fine.....are you boosting? i think it was meant to be boosted..... i picked one up when STR was at sacramento raceway this week and it looks really big for NA....maybe im wrong? try a ITR/skunk IM....

 

ttt.....yea its for boostin, and we've tried to plug the hole up, that hole is for tha iac, so i'm not sure whats left to do, only thing i can think of is that there is a leak between gaskets and ****....but anything else? thanks

 

Any adequate sized vacuum leak will cause idle surge.

There should NOT be any "open" hole in a manifold. That will let in unfiltered air - not a good idea. (unless this hole isn't "open" to the vacuum)

Shawn