99VetteFRC

I have a 03 silverado 4.8 PCM and DBW and all the truck elecronics in my Chevelle. Last week I switched to LS1 but kept all the truck accessories and elecronics. I want to switch to an SD tune but when I do I cannot get the car to run in closed loop. I am using HPT, should I swap all my air and fuel tables from my MAF tune to the SD tune or will that not make a difference?

Cosmik de Bris

How are you switching to the SD tune?

redtan

iTrader: (5)

It's not going to run well if you use the values from a 4.8 tune while running a 5.7.

Best bet is to get a base 5.7 tune data from the HPT repository and paste those values in yours. If you're doing an SD tune then you don't have to worry about anything MAF related.

99VetteFRC

I have a SD tune from the repository and I think it is from a 5.3. The 4.8 tune I have in the car is set to be really rich, it even puffs a little fuel smoke with the 5.7 in the car. I know I need it tuned after I install it but I would like to get it so the car will be driveable untill its tuned.