02 Civic EX Misfire on two cylinders only!! Can't find Help!!

[JDMJorgie]

02 Civic EX
74000 miles
Absolutely bone stock


Changed the water pump and timing belt only. Now I get a P0300 (random misfire) P0303 (cylinder 3 misfire) and P0304 (cylinder 4 misfire). I've checked everything that I could. All wires are showing the right ohms and voltage except the obvious. Replaced the Cam and Crank sensors, still no worky. Any input is greatly appreciated. The only thing out of the ordinary is that the timing belt tensioner bolt hole was stripped but I retapped it and put a new bolt in it. Thanks to all who reply.

[Manny Naber]

did you check your plugs? did you try pulling each plug wire off one by one with the car running? And check your timing with a light make sure its' set to stock still.

[JDMJorgie]

Yup I forgot to mention I put new plugs NGK V-Powers gapped at 0.44. I also swapped around coils. I went through my timing countless times including taking the belt off and putting it on again. But I've done this sort of thing a million times its nothing new. This is a freak incident I guess...

[Manny Naber]

I would re check your gaps.

[JDMJorgie]

Already did but why just two cylinders?

[JDMJorgie]

Update: coils all showing the same signals but still no spark on number 3 and 4 coils

[1civic]

Few things I would check, type of plugs, vacuum leaks, EGR, compression, Coil packs (all 4).. And "pick up" for crank/cam sensors

I'm not there, so your own your own with how to check these things correctly!

NOTE:

In theory, if you put #3 coil on #2 it should move the mis-fire to that cylinder, same goes for the injectors..

If mis-fire does not move then coil/injector would be good, you would then go to the "crank/cam pick up", and wiring, pcm..


Just my 2cents!

[Manny Naber]

Already did but why just two cylinders?

because if those two cylinders have a larger gap your gunna have a random misfire

[JDMJorgie]

OK apparently the customer had bought the car at an auction :/ go figure so we broke it down and whoever had this car before was a straight doucher. There were several slightly bent valves and the head gasket was was the cause of the two cylinders firing between each other. So a trip to the machine shop and alotta headaches later and she purrs like a kitten. Thanks you guys for the help all the tests i ran were useless there were very minimal margins to read but a lil elbow grease and old school diagnosing usually is the best remedy sometimes.

[JDMJorgie]

Oh and the valves were horribly adjusted Lol

[hellrider]

or you could have two bad cylinders. i would do a leakdown test

[1civic]

or you could have two bad cylinders. i would do a leakdown test

I think he said that already bruh bruh!!