Search the Community

Hello all, I have a 1995 R33 GTR and I recently completed an LS2 coil swap on the car. It ran great until recently, when I started noticing a slight shudder and rougher idle. Thought it was a MAF issue so I cleaned them up, and resoldered them. I also decided to clean up the plugs and to my surprise, found that plug no. 5 was completely black, and oily. Now I dont know if this is a sign of a blown cylinder or low compression, but I decided to swap out coil no. 5 and changed the coil wire, but no change. I am at my wit's end, trying to figure out what is wrong with that cylinder and would really appreciate if someone could shed some light on what to do here. I live in a remote town in Canada, and do not have access to most things people do in larger towns, so have to depend on myself to carry out any tests or check things. This has gotten worse over the last 2-3 days, as I drove the car on a 200 mile trip, which was great until I got back home and it started to show signs of running stupid rich while cruising and lean when boosting. I have checked the coils, the wires and the plugs are all good. When I disconnect the coil wires no. 5, there is a very very minor change in the revs if at all. I can hear the coil ticking and the spark is there. If the injector wasnt firing, would it foul up the plug with black oily stuff? How do I check without the car running if the spark is strong enough? Could it be faulty injector or a weak spark? Is it also possible that cylinder 5 has lost compression? Please help me Thank you.