i'm helpin my younger brother try and fix his car. at idle, the car intermittently runs on 3 then 4 cylinders after it warms up to operating temperatures. i tested the coil, and it was not testing within specs in the book. so we replaced that, the cap and rotor. we did plugs and wires about 30K miles ago. after replacing the coil, cap and rotor, it still is intermittently running on 3 cylinders. its real rough at idle, and you can really smell the unburnt fuel. when i push on the gas the motor smooths out and it runs on all 4 again. no CELs before or after the tune up. i told my brother to go pick up a new set of wires just to play it safe. i don't think it would be the distributor itself. when my old teg had this problem, it through a CEL and it ran on 3 cylinders all the time. not intermittent like this. If the new set of wires doesn't do the trick, where should i look next? am i wrong thinking its not the distributor it self? car just turned 150K.

 

Is it random or is it always the same cylinder?

Just to be sure, and assuming it is always the same cylinder, test for injecter pulse, a noid light should be used, but in a pinch a 194 light bulb can be used.

If you can smell fuel, it is unlikely a fuel issue, I would check for spark on the "dead" cylinder, use an HEI spark tester.94

 

i will check the spark next. if there is no spark at that plug, i guess it would be narrowed down to the wires or distributor. Is there anything else that sends spark to the plugs?

 

Intermittent like this sounds like plug wires arcing through each other. My car had the EXACT same issue. New plug wires and it ran 1000x better.

 

Spark is supplied by the coil through the rotor then then the cap and spark plug leads, the coils is "controled" by the ICM, there is nothing else. 94

 

i dont know if we have the same problem but my LS couldnt pass smog at all cuz i had no compression on one of my piston and the rest had low compression. i was losing a lot of power but the car was running ok. i was pretty much driving my car with only 3 piston. people tell me i might need new sets of pistons or piston rings. others just tell me to get a new motor. i hope you dont have the same problem like me or else it will be a b*tch trying to fix it.

 

wow second post I see on dead piston
but guess that all the wire harness at this point of life are toast so they crack and ground somewhere.

 

first and foremost, check for codes. regardless of an illuminated MIL, codes may be stored. next, you need to answer the question: is it always the same cylinder? or is it random? this will make a huge difference in where to go next.
also, just so you know for future reference, honda primary coils always test out of spec. i'll bet you the brand new one you bought reads over 1 ohm as well.