Code 42 help

[Revsracing99]

I have a gm performance 3.4L engine. It is throwing a code 42. The iginition module was bad and I changed it and still is is codeing 42. It is back firing through intake. Suggestion please
Mike

[jmgtp]

It sounds simple and I imagine you've already done so, but I'd start by double checking to make sure you don't have the spark plug wires crossed. Don't go by the #s printed on the coils, verify by position.

If you're backfiring out the intake I'd guess it is either firing at the wrong time (crossed wire, cps problem, bad module) or I suppose the cam could be out of phase with the crank. Does it run at all? or just pop out the intake and give you code 42?

Code 42 is for electronic spark timing. Meaning the ecm capability to manipulate spark timing over 400 rpm. Might also want to check wiring from ecm to ignition module if the spark plug wires are correct.

[Revsracing99]

I have check wire configuration it is correct. I have put a new cap and rotor on. And installed a new coil. It idles fine but under load it is back firing slightly. Wires seam to be fine sprayed them with water and run my hand down them.

Running out of ideas

[torq455]

what's the timing set at? if it's running very lean it will back fire under load too. lean mixture tends to cause a misfire and an incomplete burn. then it loads up and pops. if it's still in the intake, you may have a bad intake valve seal.

[Revsracing99]

Timing is at 10 degrees btc. But the code 42 cause the computer to retard timing even more. I'm going to take module out and see if I got a bad one. You think being new it would be good.
I have a air/ fuel gauge it say I'm running on rich side. My lap top agrees.

[Revsracing99]

Does anyone carry a performance distributor for 2.8L? Or do I need to go with stock?