hey guys i have a question i have a turbocharged 5.3l on my 2006 silverado flex-fuel truck wich worked pretty good with no problems after i tuned and then i blew it up so i got me a 6.0l from a 2001-2003 year model and i rebuild it with the same 6.0L. crank & RELUCTOR WHEEL and everything else is forged. and after i installed the 370ci. motor back in the truck its when it started to back-fire when i hit gas... in normal driving it works a little bit better, but my truck turns on nice and quick with no problems its just when i hit the gas and flore it...it starts to back fire real bad and reduce engine power turns on. right now I have the original map sensor it tune with it like when i have the 5.3l so i was wondering if the RELUCTOR WHEEL changes from a 2006 to a older model. I CHECKED everything already but i can fing the problem also i have a code that comes out almost all the time its the MAF performance sensor code P0101 so whta do you all think what could it beand sum times it cant even make a burn out it sucks real bad its just i havent had a chance to take it to my tuner so he can check whats wrong with it...... thanks for the help
by the way its on a 370ci. forged with a T76gts turbo with 11.6psi, 60# injectors, 3000 stall, meth kit, and FMIC.

 

Mechanical problems can cause what you describe also. I am not certain but think the reluctor count is the same 03-06. Could also be valves. Maybe a rocker or two have backed out? A quick compression check might be in order. The cam not timed correctly also comes to mind.

Might also try a crank relearn procedure.

 

could it be bend valves or push rods on the diffrent 317 casting heads and how would i do this- crank relearn procedure??? thanks KySilverado for the help. is theyr anybody else willing to help me out?

 

reluctor wheels did not change till the NNBS GMT-900 from GMT-800 to GMT-900

 

Yes bent/burnt valves could cause a back fire. If it sounds like through the intake it would be an intake valve. If exhaust and exhaust valve. Push rods to long.

Crank re-learn is done at the dealer with Tech II or home tuning solutions EFI Live or HPT have the ability.

Back fires are either mechanical timing, valves not closing/opening correct time or seating, or spark timing.

 

Do you have a boost gauge? Check it if its not overboosting, thats what I thought when mine was doing something similar, what kind of boost controller do you have?

 

yes it back fires through the intake also sumtimes i broke the compressor wheel on my old turbo thats why i up grade it to the t76... so it might be the heads that are mest up how could i find out with out taking them apart so i can de sure??? but will it still turn on good?.

 

JJ i do have a boost guage it only gose to about 12# of boost and i only have it with the spring 11.6# spring but i think its going to be my heads

 

OH ok, well just don't get on it before fixing the problem. Good Luck.

 

well i did a compression check on my truck today and all of the cylinders had in between 120-123 of pressure so i guess i dont have any bad cylender heads or valves and this is in a low compression engine with -16.5cc pistons WITH THE piston RINGS FILE FIT top-.022 middle one-.024 and 6.0 heads, 370ci. with 120miles brand new engine. So could it just be my tune thats wrong thats its making it back fire and go into Reduce engine power mode ?????