Recently the car started misfiring under boost.Ran perfect before. Runs fine NA and very mild boost. Above that, starts misfiring badly. Its a vortec 5.7, two GT35's and max of 10lbs of boost. I run an EBL Flash 2 and tune is solid, done by Rob (Street Lethal). Fresh plugs (TR6 GP) gapped at .028, good wires, FP is 38 lbs at the rail at idle. Only thing I can think of is my Racetronix pump going away or the parts store distributor any thoughts?

thx, Brian

 

Is there anyway you can take a log of fuel pressure under boost?? Without that you're kinda just guessing. Don't hear any too many guys running a TR6 projected plug for boosted setups most guys use the colder non projected plug BR7EF

 

Thanks for the idea on the plug. I was running the TR6 because its one range colder than the OE TR55. I thought that was enough but if that solves the problem, that'd be cheap and easy.
Right now, I have a mechanical gauge at the rail but don't have a way of data logging fuel pressure so you're right i'm just guessing.

 

No problem. Maybe try the different plug and if you can just setup your phone camera where it can see the mechanical gauge to record fuel pressure. I mean that's probably as close to a log as you'll get. Or you know step up to a Holley unit. Lol

 

I'll borrow somebody else's phone for that experiment, lol. Or cover mine in header wrap... I just looked at some datalogs before it started acting up, everything under boost; spark, fuel, temp, was perfect, figures. I'll post back when I figure it out. Good time for our dollar to tank.
Brian

 

Use a GoPro if you have one. I've used mine for various things in the engine bay while I was driving