Hey all. Car is a 2000 civic with a b18b1 swap. Had a cel for something else so i checked the codes to find p0300-0304. Random/multiple misfire and 1-4 misfire. The car runs good but every once in a blue moon i can feel it stumle and want to die at idle.

Fuel filter, plugs, cap and rotor are a few months old.
Valves are adjusted, did compression test (193, 180, 180, 195) used a MM to test coil and icm in the diz both are good. Checked map sensor, also good.
What else should i check?

 

What about the wires?

 

odd that ur problem cylinders have more compression then the non problem cylinders. are u burning oil? maybe u need to run some cleaner thru it... the injectors could be clogged. I use a injector clip ,a battery charger, and air compressor with a blow gun set at 50psi.... I spray carb cleaner thru the top of the injector. then clamp the battery charger (set at 6v-12v) + and - to the open end wires from the injector clip and give the injector a quick burst with the blow gun. sometimes I will repeat the steps a few times.....

 

Not sure about wires, they seem ok though. I misted them with a bit of water to see if it would miss and it was fine.
I meant code for 1-4 as in i have a code for every cylinder. I do burn a bit of oil

 

burning oil will lower the octane of the gas and thus causing problems.

Sounds like the engine is tired and needs a rebuild..

but then again, Im just going off the facts you posted

 

What was the other code? If you clear the codes do they come back?

 

Other code is p1457 evap system leak. I cleared them 2 days ago and nothing yet, i know this one will come back though

 

Clearing codes doesnt fix the problem. The codes are there to tell you theres a problem.


What are the plugs gapped at?

 

I misted them with a bit of water to see if it would miss and it was fine.

 

They are ngk i forget the gap but i checked specs before i put them in. And thats why im trying to fix the problem

 

I usually open my gap to 42 to get a good spark.


Im wondering if its the coil in the distrib.

 

I tested primary and secondary resistance on the coil. It runs great 99% of the time ive only felt it missing at idle a handful of times.

 

Sounds like you are saying that you ign. system is Ok And compression is within Spec... So that leaves Air/fuel. assuming your fuel pressure is good. injector testing. electrical and spray pattern test...
How much carbon did you have on your spark plugs... do you have high miles maybe (sticky injectors) Vacuum test to check for leaks causing lean condition>causing high heat>causing pre ign, possibly pre ignition only when engine is hot. ... hows your cooling system working.
Did you ever check your IAC seeing as you said idle problems
There are a few Ideas for ya! lol you know your engine better then i do so just try to take note of the driving conditions when it occurs ..LIKE a detective! and remember intermittent problems are the hardest to solve! obviously you dont need a whole engine over haul like previously mentioned... because mechanically your in spec. maybe this sparks an idea for you

 

LOL what facts...? The fact that he has a random cylinder misfire intermittently..? or the fact that his engine compression is in Spec...?
Im just curious which one of those facts tells you he should rebuild his engine..?

Oh... nice use of the word "Thus" Though.

 

The plugs all looked pretty good, i havent checked iac but i will today as well as double check for vacuum leaks. Im not sure on mileage on the injectors guess cleaning them also today

 

No vacuum leaks. Iac was dirty as hell so i cleaned it put it back then wouldnt stay idling. Reset ecu and let it relearn the idle and its good again. Just have to wait and see if it randomly hapens again

 

have you tried getting new injectors to see if thatll fix your problem?