MattSapp95_T/A

iTrader: (35)

I have a LS1 motor that is a fresh rebuild. It was running great and cruising around. As I got into power it started popping and missing. I thought it was low on gas so I pulled into the local gas station and put some fuel in. the issue has gotten worse and now it is missing on 4 cylinders.

The weird part is its on 2 separate banks.
cylinders 1 and 7 on the driver side and 4 and 6 on the passenger
i pulled compression and its all good

it does have 2 codes which is a Crank shaft position code and a p0200 (injector circuit malfunction)

I have replaced the crank sensor already and it didn't help any. Fuel pressure is good along with oil pressure etc.

Car has a custom tune

Wideband reads full lean when idling so I assume the 4 injectors are not firing (also the p0200 leads me to think that as well)

Any ideas

Thanks,

GMtechmatt

coil connector fully seated?
drag test the pin?
is it just one bank of misfires?

onesloGTO

iTrader: (2)

Check for a broken coil pack wire that may be shorting out. Just pull off the whole harness on each bank and inspect.

MattSapp95_T/A

iTrader: (35)

No as described above its 2 separate banks.

MattSapp95_T/A

iTrader: (35)

I will take a look and see how they look. Thanks!

MattSapp95_T/A

iTrader: (35)

OK put a set of good coils on it and still same issue. Pulled covers and no broken springs, good compression, injectors all ohm out properly. Makes me wonder if it's in the harness or tune

blackLS1m6

iTrader: (14)

I would start by checking your injector 1 and 2 fuses. If that's good check the misfiring cylinders with a noid light and make sure they are pulsing.