LS Swap Troubleshooting..no pedal response

[shearjs]

We had a guy come by this past weekend to go through things and do some troubleshooting. He works for the local dealership, and knows a little more about troubleshooting than we do. Overall, we ended up leaving all the new parts on, throttle body, pedal sensor, wiring from pedal to TAC. The pedal was working OK, but still a little sporadic at times, but the engine was running terrible. The fans weren't kicking on like they should, and it turns out the coolant temp in the ECM wasn't matching the coolant temp on the dash gauges. After several hours of tracing wires and clearing codes, he determined that there was a ground wire that we had grounded to the firewall, that wasn't getting a good ground, and should have been grounded to the engine. The other suggestion was a faulty engine coolant temp sender in the driver side head. I had an old 5.3 on the engine stand, so we swapped the coolant temp sender to the 6.0 in the truck. Seems to have done the trick. Truck is running smooth, electric fans are kicking on when they should, and we now have the accelerator back. Time for some more shakedown miles! Thanks for all the suggestions and ideas. It's been much appreciated.

[Houston Ben]

Hi Shearjs,
Good read and some good ideas for me to try, I have one question:

he determined that there was a ground wire that we had grounded to the firewall, that wasn't getting a good ground, and should have been grounded to the engine.

What do you mean by this? Was the ground at the firewall connected to the engine? Which ground was this, was it the braided ground wire??

Thanks,

Ben

[shearjs]

Originally Posted by Houston Ben

Hi Shearjs,
Good read and some good ideas for me to try, I have one question:



What do you mean by this? Was the ground at the firewall connected to the engine? Which ground was this, was it the braided ground wire??

Thanks,

Ben

The ground wire was one of the grounds within the engine wiring harness. I don't know exactly which sensors the ground wire was far, as all the wires are covered at this point, but it was one of the factory engine grounds that was originally grounded to the engine itself rather than the firewall. it had been so long so I'd removed the harness from the engine, that I didn't remember where all the grounds initially were. Hope this doesn't make things more confusing than they already are.

[Houston Ben]

Thanks!

[Alanj80]

Hey buddy I know this is a older post but I'm having the exact same issue. Did the ground wire perminetly fix your issue? Thanks

[shearjs]

Originally Posted by Alanj80

Hey buddy I know this is a older post but I'm having the exact same issue. Did the ground wire perminetly fix your issue? Thanks

From what I remember, the ground wires did take care of the problem. I ended up having issues with my pedal response being lost later on as well. The fix that finally took care of it was replacing the whole pedal assembly with a new ac delco unit. Hope this helps.

[Alanj80]

Thanks man, I going to recheck my grounds tomorrow.

[king-918]

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