Back-tracing calculated PID's?

[frojoe]

My Commanded AFR during cold cranking is thru-the-roof-rich (4-5:1), and I'd like to figure out what inputs/tables the PCM uses to calculate this value.

I've checked all the sensors, they're reading proper ambient cranking values. Tried multiple PCM's with stock & modified tunes, all with same super-rich commanded result. There is a physical problem here in the wiring that I have to trace.

This likely isn't as much an "HPTuners" question as it might just be how the PCM would calculate this so I can back-trace and find what physical wire is going screwy.

TAC module also replaced... could the DBW pedal be doing something screwy even though my throttle position reads fine in the scanner?

ANY input would be infinitely appreciated!

Thanks
joe

[SSUte01]

FA Mult Stage 1 & 2 during cranking have a significant role in commanded AFR. Cant view anything on this tablet but assuming you've checked the usual suspects this table is worth looking at. Little confusing at first, but you'll figure it out. Could be way off to, just a suggestion off the top of my head.

[frojoe]

Thanks for the input SSUte01, and I've looked at that table, but more what I'm asking is, logically, how does the PCM compute the Cranking Commanded AFR?

I'm not looking to tune the table, I'm trying to trouble-shoot and find what physical electrical PID's the PCM uses to calculate this parameter. I'm trying to diagnose (thru the PCM's computer logic) which physical wire(s) might be giving grounded or weird voltages, before I have to rip open the car, pull the full wiring harness, and do all the bench testing/elimination/investigation to find any wiring errors.

I should say this was a professionally-made wiring harness from a very reputable source, and the car was running for several months before stored for the winter, had some cutting/welding done on it, and then come spring time starting exhibiting this flooding characteristic, regardless of PCM or tune that was used to attempt to start it. Trying to minimize work before I tediously check every one of the 100+ wires..

[frojoe]

Bump.. anyone with any input? Any electrical logic/calculation "diagram" or "flow chart"??

I'm at my wit's end with this damn problem.

[Wilson34]

Have you checked/tried other injectors?

[frojoe]

What that change things? I've tried with injectors plugged in or unplugged, and the computer is giving same wide-open injector pulse. Measured resistances of injectors and they're all damn near the same.