94heritage

So this isnt my normal swap project. Im used to taking Engines out and putting an LS in place of something else. Well I work for a diesel performance shop and we had a customer want to remove the 6.0 out of his 02 suburban and have us install a 12 valve cummins. I know stupid but thats what he wanted. Anyways my issue is we are using the factory computer to control the 4l80e and all the factory functions. We used the factory ls tone wheel and crank sensor for tach signal and rpm for the trans. We have tps signal and the trans shifts and lock ups as it should but after about 20 minutes (watching it on the scan tool) it will just unlock the converter and will not lock back up until you turn the key off and start it back up. Then you can drive another 20 minutes and the converter unlocks again. You can do this all day long for 20 minutes at a time. Im using efi live to tune the trans functions. I have failed the maf like if it was running sd. Anyone have any insite???? Im lost here.

truckdoug

iTrader: (25)

thats a tough one. any codes to work from?

im not an oil-burner guy per se, but i'd take a cummins swapped 'burb any day.

94heritage

No codes is the odd thing

truckdoug

iTrader: (25)

thats damn weird. i never figured out my 4l80e lockup issues, but all the info pointed to the misfire count tables. eventually I just said screw it and hooked up a switch

this thread helped me check all the obvious issues
https://ls1tech.com/forums/pcm-diagn...-lockup-2.html

you could always run a standalone trans controller

94heritage

So i have noticed that the rpm on the scanner bounces around when it unlocks the converter. But does it at exactly 20-22 minutes no matter what driving style you are using. Turn the key off and restart it and all works fine