Which vacuum line, when leaking, causes a loopy idle?

 

??? How do you know that it is a vacuum line???
Low coolant could cause a lopey idle
Bad IAC could cause a lopey idle.
believe it or not, low brake fluid could even cause a lopey idle.
Give us more information

 

My car (95 gsr) and my friends civic with a gsr swap has the same problems. Some bolt was loose on my intake manifold which caused this. Try to tighten everything down if u havent..

 

Any vaccume leak would cause a crap idle. and first off, can you hear a leak? if not check one of the other sugestions.

 

whoops i forgot to check this thread, my car is fine, i was just wondering for the sake of one of my classmates who wants to fool people he has cams. same guy also like to run on three cylinders to make his car sound like a wrx.

 

take it to a shop and they can use a machine and immediantly tell which line is leaking, I'm taking my car today to get it fixed.

 

If your friend wants to be "cool" and make his car sound like that, just unplug the IACV. It fools people.

Reason I know is, I had an IACV that needed changed before, so, to stop the bouncing idle, I unplugged the IACV. It idled like a Harley then. lol One afternoon I went to the track to watch some racing, and the guy parking people was like "got some aggressive cams, eh?" lol