Help random misfires after engine build! 1,3,5,7
01-08-2015, 05:14 AM
#1
Teching In
Thread Starter
Help random misfires after engine build! 1,3,5,7 2000 Camaro LS1/4L60E.
Hey guys im having some weird misfires in cylinders 1,3,5,7. My buddy and i just got done building my motor and it ran great for about 500 miles with no misfires or codes. And now im getting intermittent misfires. When i check it with my pocket scanner it will show up with a p0301 sometimes and othertimes it will be P0305 and other times it will be p0300 and the CEL will flash. I hooked up to a better scanner and it said it misfired 400 times in cyl 1, 250 times in cyl 3, 100 times in cyl 5, and 50 times in cyl 7. but 0 times in cyl 2,4,6,8.
Heres a list of mods recently done:
-Reground Ls6 cam
-Ls7 lifters and trays
-Kaytech timing chain
-Melling high volume oil pump
-oil pressure switch
-799 heads
-AcDelco Ls1 head gaskets
-Lunati Springs
-adjustable roller rockers
-Ls6 intake manifold
-SLP long tube headers
Heres the mods before the swap
-SLP CAI
-EGR/Air pump delete
-magnaflow resonator
-SLP Y pipe
-Full suspension and big brake kit (nothing to do with problems)
-Texas tuned computer with rear 02s deleted
Any help or ideas would be greatly appreciated.
We have checked grounds to the block and added an additional ground to the block. checked grounds to injector harness and added an additional ground there too. My buddy that helped me is a corvette tech and we are both stumped. I havent gotten the car tuned yet either. It still needs to be tuned by Cunningham motorsports in Temecula
Hey guys im having some weird misfires in cylinders 1,3,5,7. My buddy and i just got done building my motor and it ran great for about 500 miles with no misfires or codes. And now im getting intermittent misfires. When i check it with my pocket scanner it will show up with a p0301 sometimes and othertimes it will be P0305 and other times it will be p0300 and the CEL will flash. I hooked up to a better scanner and it said it misfired 400 times in cyl 1, 250 times in cyl 3, 100 times in cyl 5, and 50 times in cyl 7. but 0 times in cyl 2,4,6,8.
Heres a list of mods recently done:
-Reground Ls6 cam
-Ls7 lifters and trays
-Kaytech timing chain
-Melling high volume oil pump
-oil pressure switch
-799 heads
-AcDelco Ls1 head gaskets
-Lunati Springs
-adjustable roller rockers
-Ls6 intake manifold
-SLP long tube headers
Heres the mods before the swap
-SLP CAI
-EGR/Air pump delete
-magnaflow resonator
-SLP Y pipe
-Full suspension and big brake kit (nothing to do with problems)
-Texas tuned computer with rear 02s deleted
Any help or ideas would be greatly appreciated.
We have checked grounds to the block and added an additional ground to the block. checked grounds to injector harness and added an additional ground there too. My buddy that helped me is a corvette tech and we are both stumped. I havent gotten the car tuned yet either. It still needs to be tuned by Cunningham motorsports in Temecula
Last edited by Kevin Goofball; 01-08-2015 at 05:19 AM. Reason: additional info
01-12-2015, 08:27 PM
#2
If it's got cats could be melted cat. Have a exhaust shop check it. Check power to the drivers side coils verify voltage is the same on both banks. I one time had a customers car where the power wire for the coils at the splice pack in the harness had broken inside the insulation and had the same problem you are experiencing. Myriad of possible causes.
Could be the car needs to be tuned also you can't trouble shoot until the tune is correct you are wasting your time unless it's a mechanical cause.
Could be the car needs to be tuned also you can't trouble shoot until the tune is correct you are wasting your time unless it's a mechanical cause.
01-12-2015, 08:35 PM
#3
Check your coil brackets, My Son In-laws truck had the same thing happen and the coil brackets on one side were loose so he tightened everything up and also checked his wiring and it fixed the problem. Not sure if it was the loose brackets or a loose harness though.
I guess I should have read your whole post before commenting. It does seem odd that it's one whole bank misfiring, My Son In-laws truck was showing multiple misfires on one bank as yours was though.
I guess I should have read your whole post before commenting. It does seem odd that it's one whole bank misfiring, My Son In-laws truck was showing multiple misfires on one bank as yours was though.
Last edited by LLLosingit; 01-12-2015 at 08:48 PM.
