I am working on a 2006 5.3 computer on unknown year engine that is swapped into a 1976 GMC Jimmy with a turbo 400 and other 1 ton drivetrain. I bought this as a driving swapped truck and drove if from New Orleans to Denver and it never ran good so I bought an HP Tuners and started to try and tune on it and never had any luck until I figured out that it was a flex fuel tune on a non flex motor. I now have the right injector data from the repository and it now starts and idles great but still no PE. I have also used the spark tables from a non flex fuel tune not sure if that might be causing problems or the lack of speed sensor, or the lack of transmission inputs since it started as a 4l60e. I am new to LS tuning so it might be something simple that I missed.
Thank you for your time.