VVT Delete + Stage 1 CAM Upgrade + Tune

[Fisherman Dan]

Hello, looking for some guidance. I have 2013 Black Diamond Avalanche 5.3 LS. I had machine shop rebore block and I did the VVT delete with a performance cam (stage 1). After all said and done I noticed 22 MPG on Hwy. Then I took to a qualified DYNO Shop to tune it as it was choppy idle and recommended to tune by parts factory. Now I?m seeing about 15 MPG on Hwy. Does this sound normal? Also, they did not resolve the choppy idle so I used my Diablo tuner to up the idle for park and in gear to help it not stall. Engine runs good overall but I do notice when coming to a stop you can feel it like shifting gears once or twice before stopping. I had it tuned in Colorado and drove to new home in Missouri and I think maybe I?ll just go to another tune shop. I spent $600 on last one. Anyone have suggestions, I would greatly appreciate it. Thanks Dan USAF Veteran

[blindsquirrel]

Need the tune file, and then a log file showing what it does when running on that tune. Kinda hard to spot problems based on nothing but imagining a picture of a truck.

[Alvin]

Hello, looking for some guidance. I have 2013 Black Diamond Avalanche 5.3 LS. I had machine shop rebore block and I did the VVT delete with a performance cam (stage 1). After all said and done I noticed 22 MPG on Hwy. Then I took to a qualified DYNO Shop to tune it as it was choppy idle and recommended to tune by parts factory. Now I?m seeing about 15 MPG on Hwy. Does this sound normal? Also, they did not resolve the choppy idle so I used my Diablo tuner to up the idle for park and in gear to help it not stall. Engine runs good overall but I do notice when coming to a stop you can feel it like shifting gears once or twice before stopping. I had it tuned in Colorado and drove to new home in Missouri and I think maybe I?ll just go to another tune shop. I spent $600 on last one. Anyone have suggestions, I would greatly appreciate it. Thanks Dan USAF Veteran

Honestly a cam is the easiest way to kill the mileage in a vehicle. A log and tune file will help but there are very few situations where you might see the same MPG as stock. The more choppy the idle the worst the mileage will be.

[2xLS1]

There is no telling what you did using a Diablo tuner on top of someone else's tune. Without posting the file that is in it now read with HP Tuners in their .hpt format no one is going to be able to help.

[turbobob924]

I have the same car and the same planned upgrades.
Interested in seeing your tune file!