I have a turbo Silverado ss that has always ran great until the other day. It sat for a couple weeks during a detail and the battery went dead i also changed the plugs from a tr6 to a br7ef because i was going to turn the boost up a little. Now the truck misses very bad anytime it starts going into boost, it does not matter if it is part or full throttle. I pulled the plugs and they look very lean. I put the old plugs back in to verify the new ones were not the problem and problem remained. I have meth on the truck and if i "test" that when going into boost it misses less. Fuel pressure is good and it has no codes. It is sd tuned no maf. Sorry for the ling rant i am just frustrated.

 

did they detail your engine bay?

 

Do you have a wideband in the truck? Also what's your plug gap? I was having a issue and ended up being a bent pin going to the main coil harness.. also are you sure fuel pressure isn't dropping off in boost? Are you boost referencing fuel pressure? Factory coils? Feel like it loosing one cylinder or missing on all of them.

 

No wideband but i do have a fuel pressure gauge and it is not dropping any more than normal which is a couple psi. Factory coils, stock fuel system with a 255, it is definitely missing on all. The plugs were all the same and were lean looking, all were even though. Tr6 were gapped at .35 br7ef were out of the box.

 

gap em to .025 and see if it cleans it up. if not then check for water in your spark plug boots.

 

I had all the plug wires off and they are good the br7ef were at about .028

 

Map???

 

I tried one yesterday same thing, i might have bring it to the guy that tunes it and have him look at it i was hoping it would be simple