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i have a bit of info up at the DHP forum for those of you who have access http://www.gmv6pcm.com/index.php?showtopic=5307&hl=
here is a link to the data log: http://www.gmv6pcm.com/index.php?act...e=post&id=2588
not sure if you will beable to download it or not.
I have been fighting random misfires for some time now. mostly in park, at startup, and at low speed decelrating. i have done the following to try and correct the problem:
-Plugs (iridiums and the current autolite #103's colder range) plenty of dielectric greese and had anti seize on the plugs
-wires are not even 8 months old. and tested fine with a multi meter.
-two diff sets of stock coil packs and one set of MSD coil packs all primary and secondary resistances within limits.
-tried a second ICM ignition control moduel.
-fuel filter is about a year old
-injectors are low mileage from an L67 (flow rate adjusted in PCM file)
-PCM tune: fuel trims at or less then + or - one.
OK that aside, the main prob at hand happend last night. i was data loging a run when my SES light started flashing and i slowed down and took the next exit. i was just after i shifted into 4th gear at WOT...3900RPM and 119.95 mph!. it was a P0300 Random misfires. for those of you who can read the scan i provided, it started at frame 2484 went from Zero misfires to 54. and then a few sec later up to 198 misfires engine sounded fine but for fear of not knowing what exactly was going on from the ses light i shut down the run and pulled over. after slowing down some i gave it some gas and it started showing large amounts of Knock! up to 17* [looking at the scan Engine coolent temps never went above 82*C (180*F)]
after turning off the car, i went to just key on and read and erased the code. after that the car started fine. drove home with no problems. even did a WOT run thru 1st gear and into 2nd with no KR. about 2 weeks or more ago, i went to start the car early in the morning and it started very rough. SES was flashing so i turned it right off... erased the same p0300 code and the car started fine. this morning it did the same thing. started rough and then started up fine.
Currently i know there is mostlikely a prob with the Tq converter... it will shutter under light acceleration below its stall and cause false Knock. i have tested this by pressing the brake while on the gass.... this disengages the lock on the converter and it goes away. im thinking that the trany might be to blame for the flase misfires aswell... but dont know. i was just also told to look at the crank sensor. but if that were the prob i would think it would be completely random or make probs everywhere in the power band. my only problem areas are in park, very low mph and coasting, and now in fourth gear at WOT!
here is a link to the data log: http://www.gmv6pcm.com/index.php?act...e=post&id=2588
not sure if you will beable to download it or not.
I have been fighting random misfires for some time now. mostly in park, at startup, and at low speed decelrating. i have done the following to try and correct the problem:
-Plugs (iridiums and the current autolite #103's colder range) plenty of dielectric greese and had anti seize on the plugs
-wires are not even 8 months old. and tested fine with a multi meter.
-two diff sets of stock coil packs and one set of MSD coil packs all primary and secondary resistances within limits.
-tried a second ICM ignition control moduel.
-fuel filter is about a year old
-injectors are low mileage from an L67 (flow rate adjusted in PCM file)
-PCM tune: fuel trims at or less then + or - one.
OK that aside, the main prob at hand happend last night. i was data loging a run when my SES light started flashing and i slowed down and took the next exit. i was just after i shifted into 4th gear at WOT...3900RPM and 119.95 mph!. it was a P0300 Random misfires. for those of you who can read the scan i provided, it started at frame 2484 went from Zero misfires to 54. and then a few sec later up to 198 misfires engine sounded fine but for fear of not knowing what exactly was going on from the ses light i shut down the run and pulled over. after slowing down some i gave it some gas and it started showing large amounts of Knock! up to 17* [looking at the scan Engine coolent temps never went above 82*C (180*F)]
after turning off the car, i went to just key on and read and erased the code. after that the car started fine. drove home with no problems. even did a WOT run thru 1st gear and into 2nd with no KR. about 2 weeks or more ago, i went to start the car early in the morning and it started very rough. SES was flashing so i turned it right off... erased the same p0300 code and the car started fine. this morning it did the same thing. started rough and then started up fine.
Currently i know there is mostlikely a prob with the Tq converter... it will shutter under light acceleration below its stall and cause false Knock. i have tested this by pressing the brake while on the gass.... this disengages the lock on the converter and it goes away. im thinking that the trany might be to blame for the flase misfires aswell... but dont know. i was just also told to look at the crank sensor. but if that were the prob i would think it would be completely random or make probs everywhere in the power band. my only problem areas are in park, very low mph and coasting, and now in fourth gear at WOT!
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