Help with Idle Please.

[BoostedB20z]

Hello i need some help please, i have a very irratic idle issue i cannot seem to solve. I have a 94 integra with a b20z2 swap and my idle is crazy it drops to below 1k and then goes to around 2.5k and back down all the time back and forth even if i try to hold the gas a bit to maybe 2.7k or so it will stay for a second then drop back down and shoot back up. I dont know a whole lot about this car thats why i am asking for any help the car drives perfect just a very messed up idle anything helps.

 

[jdmjim]

i would start w/the basics first vacume leak dirty throttle body then check the iac.

 

[amaestre32]

yeah what jim said probably a vacume leak or iac

 

[BoostedB20z]

how would one check for a vacum leak and what is a iac sorry im a noob

 

[jdmjim]

no prob man. the easiest way to find a vac leak is to look for any hoses off or a loud hissing noise, i like to use a can of carb cleaner and spray around hoses and manifold gaskets etc with the car running and see if anything changes. just dont spray the dizzy or the wires and exhaust manifold. the iac is the idle air control valve on the intake. it could be bad.but with a swap anything is possible.

 

[91da]

What i did is check all my vacum. That wasn't it so i replaced the iac (go to a junkyard b/c there like 200 bucks) that wasn't it. Turn's out it was just a dirty throttle body, spray some cleaner. Hope that helps a little 8)

 

[BoostedB20z]

When it idles i can hear something hissing sounds to be below the throttle body a suction sound of some sort i gotta check that after work if not were is the iac located at?

 

[jdmjim]

sounds like a vacume leak dude.

 

[BoostedB20z]

I cant find anything but i havent looked hard enough cold outside i just got this car i noticed theres alot of stuff not hooked up to things i think there just sensors but not sure they dont do anything with or without them in.

 

[FullCry]

I can't remember if the IAC valve on that engine has a screen in one of the ports or not but the older Honda engines do. If it does you can remove the IAC valve and clean the screen---if it is clogged --- and this may end your problem. But like the others said it sounds like you have a vacuum leak, like there is a line loose back there where you hear the hissing. As far as the IAC valve goes you can also spray throttle body cleaner into the ports inside the throttle body and let it sit awhile then crank it back up and this might clear it out. If you find the vacuum leak and it is still hunting for idles then try to tap the IAC valve several times if needed and if it smooths out then you know that the electrical part of the valve is bad. I have also removed IAC valves and sprayed throttle body cleaner in them and let them sit awhile then put them back on and they worked. Good luck, FullCry