dyno/misfire problem

[nino]

went to the dyno today and got shot down.
i appearantly have a misfire. everytime i get up to 5000 rpms my car misfires. therefore unable to dyno or dyno tune my car. i had just changed the plugs 2 weeks ago but the guys told me that i could have fried them within hours because i am running so rich. darn it!
so now i have to change the plugs again and then quickly take it to the dyno so not to foul the plugs before i get there. i think i am going with ac delco with taylor wires. i really dont think its a bad coil, and everybody knows you run rich with the power pack. just proof why tuning is important after the power pack!
my question is this: if i found someone with an autotap, would it tell me what plug is fouled? if so couldnt i get away with just changing that plug?
why am i misfiring at 5000 rpms only?
what would you guys recommend me doing?
the guy at the dyno told me to gap them at 36 when i put them in cause i am running so fat (my new term for today) they did install the maft+ and left it at 2% wot. but they were unable to tell me anything cause of the misfire.

[vtv6firebird]

Well first off if you are having a misfire at 5000 rpms you are pretty close to the rev lmiter, so that is always a posiblity, especially if your tach is off. If you are having a "serious" misfire it will set a code, which anyone(Autozone) can pick up with a ODB II scanner and tell you exactly which cylinder it is. You mention that you will change the wires this time, but did you change them with your first plug change, if not, this is a possibility for your misfire, as the heat on our cars where the wires run reduces their life significantly. Did you gap the plugs before they were installed two weeks ago? Just because they are brand new does not mean they are gapped for the car they are going into. But remember, you arent supposed to regap platinum plugs, but as long as they are new you can gap them.

You are misfiring at higher RPMS only becuase of increased load, and the speed at which everthing is operating. There is a lot less room for error at higher rpm's. If you really want to fix this problem, narrow it down to the cylinder on which the misfire is occuring, then check all things associated with that cylinder. But remember, it may be more then one cylinder that is misfiring as well.

Good luck

[scottblack]

Nino, when it misfired, did the light flash, or just come on? Mine does that, it flashes when i mash the gas and don't let off, i don't know what RPMs though, but it has done that from day one. I think i need to replace the coil packs, done the wires already.

Scott

[slacker69]

Nino i was doing somethinking today dont worry this is a good idea. I think for one it is cause u are running rich. But i think u should buy new plugs all of them and gap them to 35-40 if you are at stock gap with all that extra fuel and load on the engine it will do kinda what nitrous does on my car if mine are not gapped. I will at full load detanate and misfire cause what it is doing is makeing the spark on the plug blow out like a candle. Cause the gap is so big so easyier to blow out if you have a smaller gap i is much harder to blow out that is the only thing i can think it could be. Cause if it was bad coils it would misfire all the time even going like 10 mph. Same if the wire was bad. I ran on the dyno today and my gap on my plugs was to big and my car strted to detanate and i wasted money on dyno pulls. So i say give that a try and u could prob use the NGK TR6's spark plugs like all of the nitrous and forced induction uses. If u have any ?'s on need help AOL instant messege me my aol name is Crappyday21