Hey guys,

I'm having a really weird lurching problem with my civic. It only happens when the car is warm and has been idling for 15-30 seconds. Otherwise, it drives perfectly fine.

I'll be sitting at a stoplight when all of a sudden I hear the RPM's pick up to about 1500 with a slight wobble. Then if I hit the gas I get a crazy lurching: the RPM's will go as high as 3000 (depending how hard you hit the gas) and then come back down to 1500. If you go past about 1/3 throttle, then it will rev up to about 4000 and will stop lurching. However, it will continue to lurch at low throttle until the car is turned off. If I turn the car off and on again, it works fine, until i let it idle for 30 seconds, then the problem comes back.

I have even been able to keep it from happening by feathering the gas every 15 seconds when at a stoplight. But this is really annoying.

I have a code for CKF and knock sensor malfunction but I dont think these could cause the problem. New TPS and IACV didnt fix it. Someone told me it could be a vacuum leak or an ECU problem? I'm just trying to get my head around this one.

Thanks for your help

 

sounds like a vacuum leak. Maybe this will help.
Troubleshooting Idle Problems - Honda Forum : Honda and Acura Car Forums

 

Knock sensor might cause some lurching but I bet any amount of money, your answer is going to be take care of the CEL codes first and then go from there.....which is what I would do.

 

This forum is a decade old, but my 98 has the exact same issue couldn’t put it in to words better, did you ever find the cause?