laserred02

So, I drove on the highway with some spirit, nothing unusual until after. I get off the highway and come to a stop. I begin pulling out the clutch and I notice I'm not quite getting the same power as I'd expect. Then my car sounds like a Boxer-4! Like it's operating on two cylinders? This continues to happen until after, say 2-2.5k, and then it'll be intermittent, sputtering behavior until after 3-3.5k. The only thing unusual is that I'm at maybe 10k on the oil (amsoil), but I checked the oil just a day or two ago so...no idea what it could be. Literally just three minutes before that I was in 4th or third around 60, and I noticed slight sputtering around 5.2k where I hit VTEC, however that is normal. Otherwise I've only noticed something similar when I'm around 3.5k, the same sort of sputter, which began just shortly after my tune.

Mods: I have BC Stage 2 Cams with ferrea titanium retainers and a beehive valve springs, FIPK, berk headers, 70mm nvidia test pipe, challenge 76-TA-R...really nothing else done to the motor.

Any responses would be greatly appreciated. Thanks so much for reading too

Billman250

Yes you have a major misfire.

Start with basic...comp, Va, plugs, etc.

nissanfanatic

With it running, you can disconnect injector clips one by one to find out which cylinder is misfiring. The problem cylinder will be whichever cylinder causes no change when you unplug the injector.

My one instance with misfiring was a bad coil. I went to AP2 coils after that. That was easy to troubleshoot; just swap coils and perform the same test to see if the fault followed the coil.

laserred02

Does misfiring cause damage to the motor?? Or is it indicative of motor damage?

laserred02

Thanks so much for the response, the detail is extremely appreciated!

nissanfanatic

Misfiring is bad because fuel is still being injected into the engine unless the misfire is caused by a dead injector.

Billman250

Yes yes...and without ignition, the fuel acts as parts washer, taking the oil off the rings, scoring the hell out of the cylinder walls. There are some cars that shut down the injector on the misfiring cylinder, but I don't think the S2000 is one of them.

So yes, driving with an audible misfire can trash the engine quite fast.

As mentioned, unplugging injectors one at a time is the safest (for the engine and the mechanic) and the fastest way to track down a misfire that you can hear (Subaru sound)

laserred02

Thanks a lot for the thoroughness! Turns out it was a coilpack :Part