lS1 maf table changes not effecting stft in the mid to upper ranges. very lean!
I am Tuning a LS1 T56 swaped Trans am and cannot dial in the fuel trims for the life of me. i have gotten the idle to be somewhat stable but still get a stumble/ stall when coming to a stop. most likely from not having VSS connected but i have it on order. The biggest issue is the fuel trims up around 4000 hz is leaning out a ridiculous amount and nothing i change in the maf tables seem to change it. I have done hours of driving down my street and copy, paste special % like i would normally do and it hasent made a difference, I am able to make changes near the idle range with no problems but stft still jump around a little. I have tried to rule out VE by setting the enable rpm to 300 but it dident make a difference. I would have no problems running MAF only because it is a daily driver and wont see hard use. I have been trying to dial this in for almost a month now and have tried everything! please help! I have a short log and my tune attached feel free to lend me a hand, i will take any chance to learn that i can.
98 LS1
ported heads
Trick Flow cam 228/230 585 lift and 112 lsa
truck harness reworked by myself and 411 pcm
Truck MAF
06 GTO T56
No one is willing to help me out? Im trying to figure it out and educate myself instead of having the guy pay for a tuner. Any small tips would help! I completely took the Maf out of the question and tried a run with just VE and still get very lean spikes that dont change with VE table adjustments. could anything else be interfering with it?
Is there an exhaust system on the car? If not, then the O2's won't read right at all. If there is an exhaust system on the car, then replace both front O2 sensors. Also your injector flow rate table needs to be flat with a vacuum referenced fuel pressure regulator as used on a 2000 truck set-up.
And the even KPA rows of the primary VE need to be copied to the matching rows of the secondary VE. The primary table is not used in SD mode. Your Maf table is lower than stock from 2875-5625 HZ, making the AFR leaner.
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