Search:

Understood.

Doing some more reading, I see the reason for the 14.22 stoich AFR is that most fuel today is E10. Makes perfect sense and is very obvious now, I just hadn't thought about it before.
...

Your suggested PE table is right about what I was expecting to see and was thinking of changing it to... I just need to weld a bung in the exhaust for the wideband for datalogging.

Is your...

Update...

New Delco plugs and Delco wires totally fixed the issue. Fuel trims are now about -7 to -8% at idle, engine idles and accelerates extremely smooth, no more raw fuel smell, timing light...

OK, I feel like an idiot now for dismissing the "little things" as a possible cause.

After I saw the timing light working with the spark tester in place but not with the plug wire connected to the...

OK, just tried opening the tester to 30KV (~0.650" gap) and tried it on cylinders 1 and 3. No problems with either coil throwing consistent spark across that gap. And with the tester connected and...

Yes, my tester has an adjustable gap.



Not 100% sure... I attached a copy of the tune to the first post.

That's also on my list to check today. A wire with broken strands or a poor crimp will certainly show continuity with a meter but not pass enough current to operate what's connected to it.

I agree...

One of the thing on my list of things to do today is weld in a bung after the Y pipe for the wideband and see what it says.

Based on the appearance of the spark plugs I'm going with lean misfires...

Have a weird one that I've been trying to diagnose for a couple of days and still can't figure out.

Engine is a stock 2003 5.3 with a 2001 12200411 ECM with an HPtuners speed density tune in an...