do a compression check and see what you get, if you have good spark coming out that wire and it keeps missing even with new plug, you have very little compression or no
compression due to burnt valve or blown headgasket. if you check it and it has good compression then it would be an injector

 

U said spark plug is dark and wet. Is it oil wet or is it fuel wet? And, does it look like carbon buildup dark color? If it is then, you are getting oil sipping thru your rings or valve cover gasket or your compresison rings are worn and not getting adequate amount of compression to burn the fuel. Or you might have both issues oil and fuel burn which can equal to excessive carbon build up. Do the leak down test. How many miles does your motor have?

 

Could also be a distributor problem if only one cylinder is misfiring. The fact that one of the plugs is wet (again, wet with what?) says that normal combustion isn't taking place, so compression isn't a problem. If compression were a problem, you'd detect a misfire (because the cylinder isn't doing its job) but the plug would look almost the same as the other ones. So, assuming that the plug is wet with fuel, then obviously you're getting fuel, so the injector is good, but that fuel isn't getting properly ignited. This says that it's some type of ignition problem, which is usually a plug wire problem or distributor problem on a Honda. Even if you have spark, unless that spark is strong enough to jump the spark gap at cylinder pressure you'll still have problems. There is a big difference between spark strength at ambient atmosphere and at 10 times that pressure, and in the presence of fuel vapor.

Just FYI, the misfire detection on OBD2 Hondas works by comparing the crank angle and crank fluctuation sensors, so it's possible that one of those sensors is malfunctioning. Most likely not though.

 

I agree. Didn't really specified how dark the arc looked. Might have weak spark. Also, if the crank angle sensor is bad, the car will not start. Another question is what setup does he have (Hondata, piggyback or just stock ecu?).

FYI, spark strength shouldn't have any correlation with elevation pressure. I think you ment by oxygen content within the ambient air compare to higher elevation. Which will equal to less horsepower due to less oxygen entering the chamber for combustion. I'm posititve that distributor will provide similar Joules eventhough it maybe located at higher elevation (thinner air = less oxygen).

 

No, I meant nothing of the sort..

This has nothing to do with elevation at all; I don't even know why that would be relevant. Even so, I live at 5,000 feet above sea level and have a perfectly good grasp on the altitude-density relationship; its relevance to this discussion aside..

I meant it takes more spark energy to jump a plug gap at anything above ambient pressure, so it may not spark during the compression stroke when you're at cylinder pressure, not ambient pressure. Basically, just because you can pull a plug and see a spark, that doesn't mean that it will spark during the compression and combustion cycle. This has nothing at all to do with altitude; a few thousand feet in elevation is only a few PSI (multiplied by the compression ratio obviously, but it's still not that big of a relative difference). Anything other than pure air also creates an insulation effect and makes the spark harder to jump the plug gap, so add in fuel vapor and it's even harder. The higher the gas density, the more spark energy it takes to jump a spark gap of a given distance. This is all grouped under some common gaseous breakdown laws (Paschen's law, etc.) which are ultimately governed by standard laws of physics.

Oh, gaseous breakdown is also temperature dependent. That's part of Paschen's Law as related to the Townsend breakdown mechanism if I remember correctly.

If you have damaged or worn plugs wires, you may see a spark when you pull a plug, but the wires (or distributor cap, etc) might not be able to conduct enough energy to jump the gap at compression pressure. THAT'S what I'm saying.