First time posting. Got an intermittent low and rough idle on my 2007 Honda Civic LX. Will generally only idle low and rough for a stop light or 2 then things will relatively go back to normal. I've replaced most things that could be causing this which have each helped in there own way solving various problems and have helped with overall engine performance but it still has a few hiccups here and there.

Engine will also randomly develop a rhythmic pulsing with 1-2 second intervals that can only be felt, rpms do not change but it feels as though the ecu is adjusting idle/ fuel mixture to account for a fault somewhere. This generally only lasts for a stop light.

Any help is appreciated! Parts replaced;

MAF, MAP, purge control solenoid, spark plugs, PCV, fuel injectors (leaking, long crank time without priming, oil smelled heavily of fuel), fuel filter/pressure regulator, and probably a few other things.

Have attempted ECU reset and idle relearn but part of me feels I'm not doing the ECU reset correctly so it's still accounting for a fault the used to be present.

  • To teach idle to your ECU and PCM, start it, hold on to 3000 RPM until you hear the radiator fan cycle, now let go of the accelerator and let it sit idle for 5 minutes. Mission accomplished. (All electronics must be turned off prior to this procedure) Check for ignition coil status, fuel regulator, and fuel rail. Inspect for further intake and exhaust leaks, especially around gaskets. Run a scanner to read live fuel readings. Share them here. Sep 24, 2017 at 15:26
  • See though I feel like there should be more to help the ecu relearn it's parameters. But anyways, I've done the idle relearn correctly then. What do you do mean by ignition coil status? When you say fuel rail do you mean check the fuel pressure? I checked pressure about a month ago and it was bouncing around but within spec so I replaced the fuel pressure regulator, haven't checked it since. Maybe I should check it again as well as while driving around. I will post fuel trims when I get a chance to look at them Sep 24, 2017 at 17:44
  • Now if you did the idle procedure correct, RPM should not bounce off the charts. Go to Honda, they'll connect the HDE HIM Honda scanner and program it. And yes check the live fuel ratin Sep 24, 2017 at 17:57
  • Check the fuel live readings. And condition of the ignition coils, inspect around all intake and exhaust gaskets and hoses. Sep 24, 2017 at 18:07

1 Answer 1


Wanted to update this, I threw allot at that car and I think the thing that finally fixed this specific issue was replacing the engine valve guide seals. I did it myself and it was a pain but well worth it.

That car was cursed I think it had flood damage. I replaced the front axles 8 or 9 time using auto zones duralast lifetime warranty, each time the car would smooth out and after a few months would slowly deteriorate into shaking and wobbling at freeway speeds (yes I know I was shooting myself in the foot each time I replaced them with duralast axles but I was a broke early 20 something guy with too much time on his hands).

I replaced the front wheel bearings twice, once with duralast because I was broke and again with OEM, replaced the rear wheel bearings 3 or 4 times and the rear passenger side wheel bearing would always fail first and more often. The last time I replaced with OEM.

I always suspected the amp meter built into the fuse box to be bad and even found that jumping some specific pins in the engine compartment fuse box would help with drivability, don't ask me which pins this was years ago.

I finally traded it in about a year ago for a 2015 Tacoma and my life immediately got easier.

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