Subject	Misfire advice
Posted by	AirGuardZ on December 17, 2010 at 3:07 PM
	This message has been viewed 1461 times.
Message	Having trouble correcting a misfire in aft driver-side cylinder. Here are the symptoms: Engine idle: Constant misfire Parked, revving engine: Constant misfire Driving, cruise throttle: Constant misfire Driving, acceleration throttle: misfire goes away most of the time. When the engine smooths out, it stays gone until cruise throttle or (sometimes) acceleration in the next gear. Driving, wide open throttle: same as above The car used to eliminate the misfire as it warmed up, but this no longer happens. All symptoms verified by obvious rough running and a sudden drop/lack of rise in EGT from the left cylinder bank sensor. Steps I've taken so far: Isolated cylinder by pulling injector clips and listening for RPM drop Replaced spark plugs and applied dielectric grease Cleaned throttle bodies Cleaned corrosion from PTU harness connections and applied dielectric grease. Tried adjusting idle air/fuel mixture with Apexi AFC. Car is a 1991 Twin Turbo, with mods to support ~430 RWHP. If anyone has any go-to post links please post them. For some reason when I try to search, the connection resets every time. Thanks for any advice. Would love to be rid of this annoying problem. -Kel
Follow Ups	Misfire advice - AirGuardZ 15:07:11 12/17/10 Pull codes, check CAS, ohm injectors (n/m) - ZiNnYc 15:27:22 12/17/10 Thank you. Additionally: - AirGuardZ 15:45:31 12/17/10 compression test? - aceman85 20:36:13 12/17/10 149FW in San Antonio (n/m) - AirGuardZ 14:56:44 12/18/10 Re: the funny thing is it cleans up then comes back. - tognot 20:39:43 12/17/10 Sounds to me like you could be running rich? - CoHPhasor 21:34:05 12/17/10 Nice. - AirGuardZ 15:20:45 12/18/10 Insticts are definitely telling me injector, - AirGuardZ 15:29:55 12/18/10 boost leak test =/= vacuum leak test - ZiNnYc 06:24:19 12/19/10
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