tub_sephiroth

I've searched and tried many of those suggestions and still haven't remedied the misfire. My friend has a 2000 ex and it's misfiring. His motor is totally stock except for a short ram intake. His brother has an auto 98 ex also, so I tried swapping parts to see if a particular part was the culprit. We put in brand new spark plugs, swap spark plug wires, swap the cap and rotor in the distributor. The weird thing is that everytime we swap one of the parts the cel will throw different misfire codes. Sometimes, it's only misfires in cylinder one and four, sometimes it misfires in cylinder one, two, four. I checked his brand new spark plugs that he bought yesterday and they were pretty black, meaning he's running hella rich.

Anything else I should look at to cause the misfiring? Thanks.

94hatchling

check your fuel system... pressure, injectors.... also check your compression, and you are in the procsess of checking your ignition.

misfires can be a bitch to diagnose. it could very well be something with the ignition, but you would need a DSO (digital storage oscilloscope) to see the voltage pattern in that system and therefore the problem.

so good luck. if nothing else, sounds like it time to take it to a shop. hard for me to help diagnose over the interweb.

evilsolb16

also check for a crack in the intake manifold or the manifold gasket

ridin98civic

i had misfiring issues for a long time, did a tune-up, wires, plugs, cap, rotor, fuel filter. nothing changed, replaced the coil, never came back.

tub_sephiroth

You mean the ignitor coil inside the distributor, right?

ridin98civic

correct

tub_sephiroth

Dummy me. All those times swapping out the rotor, cap, and spark plugs, I didn't even reset the ecm. Today, I swapped out the ignitor coil in the distributor and reset the ecm and bam... only threw code 72 (misfire cylinder 2). So I swapped everything out and put in his old parts, resetted the ecm and only threw code 72 (yes, he did drive it around the block to give time for the check engine light to come on).

Then, with the car running, I started to take off the harness to the injectors one at a time to see if the car will react different. Here are the results:

Plug one, three, and four: engine bogged like going to die
Plug two: nothing different happened

I'm guessing that maybe injector two is bad. Going to swap injector in cylinder 2 on saturday. Hopefully, that will solve his misfiring problem.

ridin98civic

check your compression if you havent already

jjrek9

iTrader: (1)

keep us posted on what solves the problem of misfire. im also misfireing on a stock 97 civic

iNfAmOuS_E46

when u figure it out let me know i have the same thing going on with cylinder 4

https://honda-tech.com/zerothread?id=1974883

iNfAmOuS_E46

i bent valves

tub_sephiroth

How'd you know you bent valves? I haven't had time to swap out his injector yet, but will update as soon as I swap injectors. Will try compression test also. Will bent valve cause low compression?

iNfAmOuS_E46

compression on cyl 4 is 60 and it doesnt smoke so i doubt its the rings and also it creates a racket when i let off the gas