Very puzzled, LMM is throwing p0301 p0101 codes and going in reduced power mode. Idles fine, knock/msfires at 1000-1500 rpms. Has a white smoke haze. Compression test were all between 350-385. Any ideas where to even start?
Misfire code p0301,p0101
- Thread starter Vernon Stoltzfus
- Start date
Swapped injectors 1 and 3. No more p0301 code but still has the same knock/misfire.
Also changed crank position sensor. Bout to pull my hair out, makes no sense at all.
Also changed crank position sensor. Bout to pull my hair out, makes no sense at all.
Hmm, it doesnt have any of the other low compression symptoms (hard starts, black smoke)Compression seems pretty low. Mine are all right near 400-425lbs.
low compression would be white smoke/haze like you mentioned, black smoke is usually over fueling(usually), and white is typically poor combustion, IE low compression, not enough injection pressure, cold cylinder. You have all the correct components to due the magic shrinking rod trick.
All the low compression motors I've worked on before had white smoke at idle or cold but it always changed to black smoke/high egts at full throttle. But smoke aside, cylinder 7 was at 350, all the others were right @ 380. So why was cylinder 1 picking up the misfire? Also it has distinct miss/knock at 1200 rpms. Would marginally low compression make a motor knock?? Thanks for your input guys
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one thing you might try is killing one injector at a time. as you go cylinder to cylinder usually you'll hear the cylinder cut out, if one cylinder doesn't change the engine operation when you shut it off, likely you've got a bad injector.
Did that via Efilive, didnt seem to make a difference which one was turned off. Anyone have a complete LMM motor for sale?
I thought gm spec for low compression being an issue was 300 psi and below??
I doubt 350 psi is your issue. I'm still betting you have a fuel/injector issue. What are your balance rates looking like?
I doubt 350 psi is your issue. I'm still betting you have a fuel/injector issue. What are your balance rates looking like?
You are correct, below 300 or an individual cylinder that is 50 +/- from the average of all 8 is what my manual tells me.
Balance rates look great, they range from -1 to +2.5
Update...
Fixed maf problem, that solved the reduced power mode.
Not getting any codes at the minute but still have a bad misfire.
Fixed maf problem, that solved the reduced power mode.
Not getting any codes at the minute but still have a bad misfire.
Yes it follows desired.
Rail pressure and pulse width will surge up and down whenever it misfires
Still fighting this issue, put in new ecm and crp sensor, no diff. Put it all back together and ran it for awhile. Now i have injector 1,4,6, and 7 control circuit codes. Wiring harness maybe?
