TB 5.3 lsa supercharged lean on one bank rich on other.

[curtmgulla]

I have a 2007 trailblazer 5.3 engine is built ls9 cam with lsa supercharger. Running e67 ecm with SD patch. Fueling looks good idle and cruise but as soon as engine hits boost and goes into PE. Bank 1 goes dead lean 1.80 lambda. Bank 1 o2 sensor drops to .0020mv. But Bank 2 goes rich! .989mv. And engine stutters bad and won't build power. What would cause one bank to run lean and one to run rich. Zero leaks in exhaust or intake. All injectors ohmed 15.5 ohms. No ground issues found.im at a loss. Using fic 1000 injectors.

[curtmgulla]

Here is log.

[Alvin]

I'll bet it has a miss on the drivers side.. Check wires/plugs/etc

[curtmgulla]

I'll bet it has a miss on the drivers side.. Check wires/plugs/etc

Logged misifires on all 8 cylinders zero miss. It's as if all 4 cylinders on driver side go dead. As the engine stutters bad as soon as it hits pe and boost. But bank 1 goes dead lean and bank 2 is dead rich.

[curtmgulla]

Any more help. Have done all new plugs and wires. Have swapped injectors from bank 1 to bank 2... still same result.

[blindsquirrel]

Confirm that neither O2s nor injector harness is going to the wrong bank.

[curtmgulla]

I have I have checked each wire at each injector against gm wiring diagram and each coil and each oxygen sensor. All.vonnecyors are in there correct location.

[curtmgulla]

so further testing has shown that while watching the injectors during pe and above 140kpa bank 1 injectors turn off bank 2 stays on but bank 1 shuts down during a pull using a noid light injectors stop pulsing on bank 1.. and i did check power is still there 14.6v... what in the tune can cause this in anyway???

[Alvin]

The tune cannot cause that to happen. It might be a bad ECM.

Maybe you should post another log. What your saying is happening is highly unlikely unless its just some sort of weird mode of failure for the ECM.


I had one go to IAT -40 F at wide open throttle. SO a bad ECM is possible.

[Tunercharged]

Perhaps consider connecting a wire at ecm that goes to control the injector bank and read voltage while driving. Use a thin wire, like twisted 32AWG, and just twist on the pin, then plug the connector. View with volt meter. Going to have to figure if ecm or harness. Also be sure to verify all harness ground connections.

[ivan.f40]

Some day a customer bring to me a Cherokee trackhawk whit a new big supercharger and had same problem.... and the issue was that bank 1 map sensor was connected to the throttle map sensor so bank 1 was reading throttle pressure and bank 2 was reading superchger pressure thats why reading was so different and there was bank descompensation.

hope works for you..

[blindsquirrel]

The non-supercharged E67 OS does not have the ability to use multiple pressure sensors. The factory supercharged ones do, but that's not what the OP has.