D75
September 19th, 2014, 12:44 AM
Ok, we're past what my other thread was looking for.
Are there any GM techs or engineers on here willing to provide technical assistance to me and my tuner?
I finally after 4 years finished my car, got it running with a mail order tune, then dropped it off at a known dyno tuning shop for what was supposed to be a one day, easy tune. It has been there over a week now and the tuner/owner of the shop is still chasing issues.
Short version: 2008 LH8 5.3 with LS2 intake/fuel rails, custom ground comp cams 224/224 .563 lift 112 LSA cam, donor truck (2008) dbw throttle body, C6 dbw pedal, TKO 600 5 speed, custom harness, and brand new E-38 ECU 12612384.
Mail order tune used a 2007 Silverado 1500 baseline. Car started and ran, but had multiple random misfires, too rich bank 1 and 2, mass air volume fault, and etc. I replaced all injectors with stock bosch injectors and I replaced the MAF and MAP sensors just to be sure they weren't the cause. The donor LS2 injectors were stuck on initial start, but we freed them up after tapping on them.
Took it to the shop and dialed all that stuff in, no more codes except for the CASE relearn code. Car was stuck at 4000 rpm. Tried completing the case relearn using Tech 2 and by applying the appropriate ground and voltage inputs for the brake and neutral safety switch. The car accelerated past 4000 rpm and actually made 362 rear wheel HP on a dynatech dyno. Shut the car off and restarted it. Again, the CASE relearn came back and limited the car to 4000 rpm. Tuner tried to satisfy every possible input the ECM was asking for but the CASE relearn procedure continues to fail to complete.
Thought maybe the baseline didn't match the service number for this ECM, so tried a 2008 6 speed Corvette full reflash. Now the car will not start. Tried to delete VATS and etc, but still will not start. Throttle body does register and cycle properly, the MAF sensor and MAP sensors read appropriately, but no spark. I do not have a starter relay going to the ECU as I am running that separately. Thinking that the starter circut needs a resistor to fool the ECM. Did not have that problem with the truck operating system, but the CASE relearn procedure still had issues.
The tuner is now searching for more info, but has not been successful. He isn't new to this and uses EFILive, GM SPS, Tech 2, Motegi, etc, etc.
At this point, it would be a huge help if he could speak over the phone with a GM tech to help weed through all of the myths and misinformation out there on the web, choose the best starting point OS for this application, and figure out what inputs and pins need to be modified to give the ECU what it needs.
Are there any GM techs or engineers on here willing to provide technical assistance to me and my tuner?
I finally after 4 years finished my car, got it running with a mail order tune, then dropped it off at a known dyno tuning shop for what was supposed to be a one day, easy tune. It has been there over a week now and the tuner/owner of the shop is still chasing issues.
Short version: 2008 LH8 5.3 with LS2 intake/fuel rails, custom ground comp cams 224/224 .563 lift 112 LSA cam, donor truck (2008) dbw throttle body, C6 dbw pedal, TKO 600 5 speed, custom harness, and brand new E-38 ECU 12612384.
Mail order tune used a 2007 Silverado 1500 baseline. Car started and ran, but had multiple random misfires, too rich bank 1 and 2, mass air volume fault, and etc. I replaced all injectors with stock bosch injectors and I replaced the MAF and MAP sensors just to be sure they weren't the cause. The donor LS2 injectors were stuck on initial start, but we freed them up after tapping on them.
Took it to the shop and dialed all that stuff in, no more codes except for the CASE relearn code. Car was stuck at 4000 rpm. Tried completing the case relearn using Tech 2 and by applying the appropriate ground and voltage inputs for the brake and neutral safety switch. The car accelerated past 4000 rpm and actually made 362 rear wheel HP on a dynatech dyno. Shut the car off and restarted it. Again, the CASE relearn came back and limited the car to 4000 rpm. Tuner tried to satisfy every possible input the ECM was asking for but the CASE relearn procedure continues to fail to complete.
Thought maybe the baseline didn't match the service number for this ECM, so tried a 2008 6 speed Corvette full reflash. Now the car will not start. Tried to delete VATS and etc, but still will not start. Throttle body does register and cycle properly, the MAF sensor and MAP sensors read appropriately, but no spark. I do not have a starter relay going to the ECU as I am running that separately. Thinking that the starter circut needs a resistor to fool the ECM. Did not have that problem with the truck operating system, but the CASE relearn procedure still had issues.
The tuner is now searching for more info, but has not been successful. He isn't new to this and uses EFILive, GM SPS, Tech 2, Motegi, etc, etc.
At this point, it would be a huge help if he could speak over the phone with a GM tech to help weed through all of the myths and misinformation out there on the web, choose the best starting point OS for this application, and figure out what inputs and pins need to be modified to give the ECU what it needs.