bad running

My 90 Civic EX has a 1.6L with multi-port FI. It sounds like it's not firing on all plugs, timing light looks normal. Mechanical timing checks out OK. New plugs were carboned up after only 2-3 miles. Any fuel problems that would cause this? It has 186K on it, original fuel pump. Having the injectors cleaned did not help, also changed the fuel filter. Any ideas?

Thanks
civicex90

your car is running too rich, running too rich causes the spark plugs to carbon up and will make your car run rough a bit, i would check your fuel pressure. Also check to see how dirty your air filter is, clogged air filters might do that.

dirty air filter and check your fuel pressure, also check your ECU and see if it throwing a code..a bad map sensor could cause it and/or a bad O2 ensor could also...


gunnmen01

First off, thanks for the suggestions.

The fuel pressure and regulator were fine. I metered the injector resisters, they were fine. I metered the spark plug wires, they read 8K ohms, which is good, no drop outs bending the wires. Pick up coils in the distributor were good, cap and rotor OK. Coil metered OK. As a shot in the dark, I put a new igniter module in it.

Finally took it to a shop, they found that at high voltages my spark plug wires were leaking, so I had very poor spark. They had about 45K on them. Changing the wires fixed the problem, and the clean injectors gave me more power in the lower revs.

Next time I won't rely on just an ohm meter test of the wires.

cool, another EX owner... word of advice though, save up for another engine soon b/c for some reason EX's tend to have major engine probs after 150k I've never heard of another car or any of the Si's having that problem just the 90/91 EX.

Hey man, I hope you stay around the site and continue to post, cause you sound like you have a lot of knowledge about cars which is what we like to have around here.

You dont want him cause of his brain, you want him to stay just so there is another 4door around here, man, ur worse than a whore, all you care about is what he drives ;) lol, j/k bro

well, it would be nice to have another 4door around here too.

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