I have eg civic coupe w/b18c1, when i start my car, and let it sit, the idle is jumping up and down. sometimes it jumps up to 3-4grand, its annoying. Im thinking its the (IACV) idol air control valve, but they are expensive and ill be pissed off if i buy it and it doesnt fix it. A buddy of mine told me it might just be a vacuum hose leak or something. I plan on getting a skunk2 intake manifold this week, what kind of IACV should i get for it, or does it use stock sensors. IF anyone had this problem or know any information on it, it would be appreciated. thanks

 

Check all vacuum connections

 

check vacum leaks, spray wd-40 all round ur TB and intake manifold, if there is a leak it will get sucked in and u have found ur problem ---still no luck take ur TB off. Then take ur coolant bypass off, there is a little white plastic screw that comes out, if thats unscrewed that will mess up ur idle for sure. So try all those things usually IACV doesnt take a **** sooo, most likey a vacum leak or that coolant bypass. Also dont screw up ur gasket for ur TB, that will create a leak if u rip it.

Good luck.

 

adjust your Idle screw in a bit sounds like it may be to far out that will make idel jump, also maybe try bleeding out your coolant, get any air out of the system, other than that check all vacumm lines and I/M gasket

 

i have the same problem...only mine doesnt jump up high...it idles really low and moves up and down about 300 rpm...this helped me a little:

start your car
reach behind the intake mani and unplug the sensor
car should idle REALLY low
adjust the idle screw on the throttle body till you read about 750 rpm
plug the sensor back in
check to make sure it stays at around 750
adjust if needed
reset your ecu

this helped me a lot i stay at around 500 rpm...i still need a little fine tuning and a check for vacc leaks...let me know if this doesnt make sense

good luck
Josh

 

i checked out my throttle body, and the screw that you can adjust is all stripped out. it looks like someone was trying to fix it before and messed it all up. Should i just get a new throttle body which i was planning to do, and will it come with a new screw, because there is no way i can get out, or adjust this one.