Mysterious Cylinder Misfire
Last edited by SouthSideBenz; Jun 2, 2018 at 09:36 PM.
Last edited by homeofstone; Jun 8, 2018 at 12:19 AM.
Any info would be greatly appreciated!!
Thanks,
Cody
I HAVE SAME ISSUE WITH CYLINDER 3, AND HAVE REPLACED EVERYTHING, INCLUDIN A NEW INTAKE MANI...NEW MAF,...NEW PLUGS...NEW COILS....I EVEN DE-CARBONIZED AS BEST I COULD..
STILL, CYLINDER 3 SEEMS STUCK, FOR LACK OF BETTER WORDS...
I EVEN CLEANED AND SWAPPED THE FUEL INJECTORS, AT THE RAIL, JUST TO SEE IF IT STAYED ON CYLINDER 3 (MISFIRE) AND IT DID...
OH, FORGOT TO MENTION TOO, LOOSENED EXHAUST MANI TO R/O CAT...NO DIFFERENCE...
I DO GET CYLINDER 2 MISFIRE 2, SO, OF COURSE THE P0300 TOO, THOUGH I THINK ITS COMPENSATORY, AS THE PLUG WHEN PULLED IS CLEAN...
I PULL NO CODES FOR CAMSHAFTS OR CRANKSHAFT SENSORS....BUT, WAS THINKING OF TRYING THAT, AS A LAST DITCH EFFORT..
I AM ABOUT READY TO PARK WITH AN "AS IS" FOR SALE SIGN....CUZ, QUITE HONESTLY, I AM TIRED OF THIS B.S. KEEPING ME UP AT NIGHT!
plugs, coil, and wires multiple times
MAF
Fuel pump, and filter
Crank pos sensor, and connector, and wire harness
Intake manifold gaskets, and all vacuum hoses, maf gaskets, slide gasket
compression checks good, cyl leak down good, no air leaks
exhaust back pressure good
Vacuum 16" at 3000' altitude
ohm all coil wiring grd and to computer
rpl EGR valve and smoked manifold no smoke leaks
also endoscoped cyl 3 looks good
I am thinking this may be some kind of electronic gremlin because it runs great till you hit 4000 RPM under a load any suggestions would help. Thanx.............
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plugs, coil, and wires multiple times
MAF
Fuel pump, and filter
Crank pos sensor, and connector, and wire harness
Intake manifold gaskets, and all vacuum hoses, maf gaskets, slide gasket
compression checks good, cyl leak down good, no air leaks
exhaust back pressure good
Vacuum 16" at 3000' altitude
ohm all coil wiring grd and to computer
rpl EGR valve and smoked manifold no smoke leaks
also endoscoped cyl 3 looks good
I am thinking this may be some kind of electronic gremlin because it runs great till you hit 4000 RPM under a load any suggestions would help. Thanx.............
Yes, I did! I searched and searched for the issue and couldn’t find it. I took it to the dealer and they couldn’t figure it out. They tried everything. They scheduled me to come back when the head mechanic was there but it turns out somehow one of the things they reset with STAR unintentionally fixed it. I had tried everything with my little icarsoft. It is likely a computer malfunction that they will have to reset. Hope this help!!
Cody Cameron
Misfire on cyl 8, swapped coils/plus/wires. Misfire stayed on cyl 8. Checked compression, was low. Camera to the bore revealed scored cylinder wall.
Not sure how that happened, I heard oil pumps go back and don't feed cyl 8 enough... time for a new engine.

It's not bad enough to rip it apart. I have changed coils plugs, cam solenoids, (I was getting a code for the cam solenoids). Nothing has had any effect. Plugs that came out were nice and clean. Changed them anyway.
I just drive it. It never seems to get any worse, but sometimes it is less noticeable.









