inconsistrnt misfire on ls3 swap

[ls3ws6]

Ok i swapped a ls3 into a ls1 f body and everything know gets power but the dome lights some time randomly come on and i have a inconsistent firing order what could that be?

[cammed goat]

As for the dome light, sounds like a body control module issue. As for the firing issue, could possibly be a loose connection at a coil pack, a possible loose spark plug wire, a vacuum leak or faulty throttle position sensor. I could be missing something and others will chime in. Check your spark plug wires and see if they click into place.

[cammed goat]

Check your grounds as well.

[ls3ws6]

Allof these are good have a 1x cam sproket and 24x. I check every connector on the wiring harness 2 all things are grounded also. I heard the lights can be from vats. Could the firing order be from that to?

[cammed goat]

I don't know about the firing order, but VATS could cause drivability issues if it doesn't shut down the ignition system altogether.

[Knight]

I'm assuming you had the PCM tuned for the new motor?

[cammed goat]

I'm assuming you had the PCM tuned for the new motor?

^^this.