Hey guys,
Being this is more of a finesse troubleshooting issue, I figured I'd seek out your guys' help in determining why my LTFT's are so negative. To be fair, I'm unsure as to what they were on the original motor as I never had a reason to log them.
Since shattering a piston skirt on the original motor, I had a forged shortblock built, had the heads pocket ported and cats deleted and re-assembled the motor, and am currently working with an excellent tuner to get it all straightened out.
The main issue I'm having that has us concerned is the LTFT's are ~0.88 and .92 for banks 1 and 2 respectively - not good. The truck got brand new OEM injectors when I did the motor and it runs great. Apart from some knock on the hit, it pulls very well for a stock turbo truck and I'm pleased with the way it drives under almost all conditions. These negative LTFT's have me concerned, though. It runs too good to have leaking injectors, and I'm just out of ideas as to why this thing is pulling so much fuel at idle and cruise.
I have logs galore if anyone is interested in viewing. I just don't know enough about the modelling and tuning aspect to fully understand what changes I've made - or need to make to get the trims back in check. My tuner and I agree that porting the heads shouldn't have as drastic an effect on fuelling (if anything the truck should be adding fuel for the flow increase I would think).
Vacuum and exhaust leaks, although they would typically result in a positive LTFT reading, are nonexistant.
Any advice would be greatly appreciated, thank you in advance.