Celica Forums General Discussion General Missfire 2k gt-s

Hey guys,

So, I got a P302 miss fire code. So, I pulled out that spark plug and discovered that there is oil in all the spark plug wells. I did buy a new valve cover gasket and install the gasket. But I'm still got the code. I will run you a list of stuff that I have checked and ya'll could tell me if I missed something. I Checked the ohms on the fuel inject and on coil pack. I have checked the voltage on the fuel inject and on coil pack. Those results where all in the same area. I also checked the connections and they all had voltage. So a day later worth of driving I discovered that the new plug I installed in that (dead cylinder) has black crap all on the electrode. I also, checked the other spark plugs and they all looked normal. So, I also switched that plug with the one next too it and see if it made a different. But it didn't. I checked if there is any weird color smoke but there is not, but it does smell like gas out of the tail pipe. I have checked and see if I had a vacuum leak, but I don't. I checked the MAF, but it was all good. I did ran some Royal Purple fuel cleaner and it still ain't making a difference. When I get back home I'm doing a compression test and post those results. I'm still all kinds of confused what it might be. But I appreciate ya'll tying to help!

From your description of the new plug's electrode looking black, sounds like either no spark is actually getting to the plug or maybe your piston rings are shot in that cylinder, fouling the plug with oil, but bad rings in just one cylinder would be quite odd. In the good old days, you could just unplug the spark plug wire boot off the plug, unbend a paper clip to make an "S", and stick the paper clip into the spark plug wire boot, hold the boot so the paper clip is about 1/4" from metal, crank the engine and watch for spark on the spark plug, but with all the electronic stuff now, I don't know if that would be a good idea.

just a stupid bit of advice, check the length of the wire going to the coil, i had a rat chew on one once and it would check out as being good but when i cranked the engine it was shorting out on the block. took me way to long to find it.