I have a 2000 Civic DX that was had CEL codes with misfires on all cylinders. Replaced the ICM, coil, cap, rotor, wires and plugs. The misfire lessened, but was still there.

I replaced all 4 injectors and now the car doesn't misfire, but idles low and rough and feels like an anchor is tied to the bumper! After a couple laps around the block, it improved, but the car still chugs a bit and also is doing a "pfft pfft pfft" heard through the exhaust.

I double checked that everything was tight. All hoses and lines were attached and all seems fine.

Any ideas? Maybe pulling the plugs and cleaning them will help? I did notice a pool of either fuel and/or cylinder blow by in the intake manifold when I opened the throttle body flap. Possibly this fouled the plugs?

Thanks!

 

Did you unplug the battery? You need to unplug it and let the ecu adjust the fuel map. And what injector size and is it new/used?

 

so you had some misfire codes and decided to start throwing parts at it hoping you would get lucky..? i can't say i'm surprised it's not fixed yet.

why is it misfiring? try finding out..

-confirm spark and valve timing are in spec.
-test for compression and cylinder leakage
-triple check your work

you also have the option of purchasing the Helms Factory Service manual for your vehicle and following the diagnostic flow to reveal the true root cause. or pay a qualified mechanic to find it.

 

I have enough experience with diagnosing, modifying and repairing EFI engines, so this is why I am here. First thing I always do when working on an engine is remove the battery cable.

The misfiring stared 8 months months ago. Replaced the cap, rotor, plugs and wires and was fine for several months. Started up again and replaced the ICM, coil and rotor - which looked kinda chewed up but the cap was fine.

Started misfiring again and this time was getting misfire codes all all four cylinders. At this point, the only thing is either burned valves or a fuel problem.

This is my GF's car and I live 80 miles away, so she had a Honda dealer confirmed it was bad injectors. They wanted a large amount of money to do the work that I am able to do and these cars are incredibly easy to work on.

BTW, we're selling the car anyways, so purchasing a Helms manual is a waste of money and I have above average knowledge in cars. This one has me stumped and perhaps someone here who knows these things well has an answer or idea?

Thanks in advance.