93 civic w/ b18a

[rossyrossb18a]

have a little problem need some help..... when i start the car it runs at 3000rpm.... after it warms up the car runs anywhere between 15-1700rpm.... why is this happening???? what am i missing or over looking that would cause such a problem??? any help????

 

[97h22dxcoupe]

check your vaccum lines make sure they are correct and also check your tps censor and map.. if this helped you plz rep me up..

 

[murray195]

First off, I'd pull down that CEL check plug on the passenger side sitting above the ecu. Jump it with a paper clip, turn your ignition to the run position, and watch the CEL flash your codes. Long blinks are 10s and short ones are 1s.
Eg: Long, Long, short, short, short = code 23
I would guess you're throwing an Iacv code or map sensor, or heated 02. If you aren't throwing any codes, check your coolant level. If your idle is hopping up and down, you may have air in the system. One really easy way to check for intake leaks is to get a can of ether (aka quick start) and sparingly spray around your vacuum lines individually. If you have a leak, chances are your rpm will increase on its own. You don't have to rep me lol! Best of luck, pm me if you like with any more questions.

 

[rossyrossb18a]

i am not pulling any codes. haven't had any codes period. and its not "hopping".... it is strictly staying at about 1700rpm....

 

[murray195]

Have you tried setting your idle? Start the car, have a flat head screwdriver ready. Let the car warm up, then unplug the iacv and manually set your idle off the throttle body. Once the idle is where you want it, turn off the car. Disconnect the battery for a few minutes to clear the iacv code you'll have. Then reconnect the iacv, then the battery. Your idle should be better now.