dices543

It's a bit hard to explain so bear with me. I have a 97 gsr in my 96 civic.

During the winter when i turn my car on it idles at 2k rpm on neutral. When the car is warmed up it still stays at 1.5k rpm. When im driving and say im braking i shift into neutral and the rpm's shoot up to 2k rpm until the car comes to a complete stop. When car comes to complete stop it drops back down to 1500rpm. If i drive for like 15min after car is warm and then shut it off and turn it back on the idle comes down to 950-1krpm when fully stopped, but while moving in neutral stays at around 1500rpm

Now during the summer its the same except when i turn the car on its at 1.5k and stays there, doesnt drop to 1k unless i turn the car off and back on after driving for few min. Same thing again when the car is moving and im braking and shift into neutral it shoots up to 1.5k, When i come to a complete stop it comes back down to 900-1k. During long trips 2hours or more when i come to a complete stop my rpm drops to 500rpm.

I have cleaned the IAC 2 times now over the past year, my motor doesnt have a FITV under the throttle body so i cant clean that lol, ive check for vacuum leaks and havent found any leaks. The only leak i found is my Cam seal is leaking and im going to be replacing that as soon as i get my golden eagle in the mail. I've tried 3 different Ecu's. p72 a jdm p72 and a p75 and the engine still idles like this. I have no CEL btw. I have also tried adjusting the idle screw.

Any help would be appreciated

B16B4NG

What happens if you cover the idle air holes in the throttle body? If the engine stalls then its one of those valves (fitv, iacv)..replace
If the rpm stay the same, then place your whole hand over the throttle body opening and see if there's suction and the car's about to stall, If it does then check to see if the throttle plate is closed all the way and there aren't any gaps between it (you can adjust the opening via butterfly valve screw next to it).
if the car doesnt stall and the idle stays the same, check to see if the intake manifold and throttle body are bolted down correctly..
if THIS isn't it, check to see if there aren't any vacuum lines leaking by spraying some carb cleaner on the hoses and check fluctuations in the idle. and also check pcv valve and other things that connect to the intake manifold.
if THIS isn't it... hmm not really sure what else could be causing it.. but your problem lies within something up there... or you could have really bad luck and all 3 ecus are bad..

of course your problem could be a combination of all these things, so once you pinpointed a problem and idle is still funny go through the steps again ensuring all problems are resolved

the cam seal would have nothing to do with the idle.. but you should get the leak repaired anyways

Former User

If you unplug the IACV when the engine is high idling, does the idle speed decrease?

Is your throttle cable adjusted too tightly? It should have as much as 1/2" of slack.

Any CEL codes?

dices543

My tb only has one hole on the top and when i do cover it the engine stalls. I'm guessing that my iacv is bad then.

Yea the car idle goes down when i disconnect the iacv, and my throttle cable isn't too tight i have some slack but not too much. And there are no CEL codes, only when i disconnect the iacv it comes on.

B16B4NG

sounds like the culprit

Former User

You may want to check the TPS and the ECT sensor.