ok, i've been having problems with my ej8('98 civic ex) and low idle. and when i mean low, i mean around 250 rpm low. stock is supposed to be 750 rpm. nothing has been touched on the motor itself(d16), it has basic bolt ons.

well, over the past few weeks, i'd say that it's cut off on me two times. it starts right back up but i'd like to get this fixed.

any ideas?

 

warm up the engine to normal operating temp, unplug the AIC, then engine will start to sputter and may even stall, then you should turn the idle adjustment screw until your rpm gauge reads about 450. Shut the engine off. Plug back the AIC, reset ECU and It should be around 700-800 next time you start it up.

 

i forgot to mention, it only idles low after the car has been driven and you come to a stop at a stoplight, etc. if you start the car and don't take it out of park, it's fine. so, adjusting the idle screw is not going to solve the problem.

 

i believe the iac gives alittle higher rpms on cold start up?

 

pcv valve might be bad.
clean out your throttle body.
grease built up around the butterfly blocks the air needed to idle.
and u can adjust the butterfly opening too.

 

Sounds like the IAC is not controlling your idle. I would also unplug the IAC while running with the engine warm and make sure the idle is at 450. If the screw won't effect the idle, it may indeed be a dirty TB. Once set at 450, plug it back in and clear your code. If the idle doesn't raise to 750 then you need to check for voltage to the IAC. If the IAC is getting voltage, then it is probably also carboned up or bad. Saying the idle screw is not the problem because it idles while cold is not neccessarily true because the ECU is in default until the ECT reaches temperature.

 

i had the same problem it was my iac. those things go all the time on hondas so i had an extra one laying around luckly.

 

ok, i'll check out the iac and clean the throttle body again. haven't done that in a few months.