0411 swap done, did crank relearn...now it doesn't run

Crazydavez28 said:

Since you did 0411 swap Check the injector bank assignments in your tune. Also LS firing order is different than SBC.

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gearheadE30 said:

Thanks the tips - it's all fixed now. The base tune I was using was the L31/4L60E express van tune, so it was already set up properly for the L31. Just a few worn out parts, a bad brand new part, plus a more sensitive misfire calibration added up to a truck that didn't want to run.

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gearheadE30 said:

Like the title says, I got my 0411 swap done on my 2000 Tahoe Limited and works great. I have EFILive and am not new to tuning, so it wasn't too big a deal. However, when I was going through the checks after getting it running, I discovered that CMPRET was about 38 degrees. I should have had a code off that far with the original ECM, but I didn't that I'm aware of.

I wasn't able to get the distributor clocked enough to bring that number down any further, so I checked and found some pictures online and it appears that the distributor was a tooth off. Set to cyl 1 TDC, pulled and reclocked the distributor, and now everything looks like it should. Reinstall, dial it in so CMPRET is between 0 and 3 degrees, and I figure I'm golden.

Except I'm not. Pending P0300 for tons of misfires, and TCC lockup shows disabled due to misfires. It also doesn't idle at all (instantly stalls after starting), which tells me that timing is off...but if CMPRET is 0, how can timing be off. It will run if I keep my foot on the gas.

What did I do wrong? Is there something else I missed in that procedure? I've never heard of setting the cam position retard causing new problems, and searching turned up nothing at all.

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badco said:

Ive picked up mpg by 3 using a msd 8.5 super conductor wire over brand new ac delcos on my 96, just some info for the future. Ive had issues similar to that due to the ground wire from head to firewall was loose and made a multiple missfire code #1 #5 #2 all would show missfire. The short 3/8 bolt in head where ground was attached was backed out ended up being problem

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charrijr1 said:

Did you use all the slots from the set up sheet. Cause I had wires left over and not enough of some others red black and left over greens and 2 blues gray/black wire not connected.

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gearheadE30 said:

Yeah, bad engine grounds will cause all kinds of strange behavior. I'm not sure why your fuel economy would change with different plug wires unless you had some other issue causing intermittent misfire or miss on a cylinder before. Which, with a V8 at part load with an automatic transmission can go unnoticed fairly easily.



You should not have any wires left over, or any wires unused. There were a few wires that needed to be spliced together to a single pin on the 0411 that were separate pins on the black box, though.

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