EFIDynoTuning Forum

I am having issue with my SCT custom tuning on my 2v 5.0 Stroker Mustang supercharged. I am facing lean spike when accelerating slowly with constant, barely partial throttle. The AFR will got to 17-20 at low rpm 1100-1900 with light partial throttle. When i try to switch of the Adaptive learning control switch to "0" to disable it and start tuning the STFT B1 and B2 the vehicle will have no issue with lean spike but once i get the Adaptive control switch back to "1" i will have the issue and will drive me crazy. when i look to my datalog i see the injector pulse width B1 and 2 follow each other with no issue. my STFT B1 and B2 kind of playing around with -15%. I tried to disable the Coasting Fuel shut off with no lock to solve the issue.

Any idea of what causing the Spike lean at low rpm?

appreciate your usual support.

that means your fuel isn't dialed in

make sure your not clipping the injector max limit

I have dialed the fuel as per your recommendations at the website. I have scaled the MAF Transfer function by divided it by 2 and scaled the injectors as per the data from your Injectors Flow data at the website and divided it by 2. I have also scaled the Intake volume, Engine Displacement all divided by 2.

I have the Siemens Deka 60 lb/hr @ 40 psi. My fuel system is a standalone. It's Aeromotive A1000 Return Fuel system with Speed Controller.

- Fuel Inj Breakpoint == 0.0000169
- Fuel Inj high slp == 0.0084500
- Fuel Inj low slp == 0.0088600
- Fuel Inj Min pulse width == 0
- Fuel Inj Pressure drop ==39.15
- Inj Comp for Pressure == 1.0
- Fuel Inj Breakpoint, High slope, and Low slope Multiplier FordeltaP == For left column DeltaP from top to bottom (127.89 , 74.96 , 70.029 , 60.0 , 30.019 , 0) and the right column for multiplier all set to 1s
- Fuel Inj offset Multiplier FordeltaP== For DeltaP from top to bottom ( 127.692 , 74.96 , 70.029 , 64.949 , 60.00 , 30.019 , 0) and the right column
for multiplier ( 1.2382 , 1.1845 , 1.079 , 1.0771 , 1.00 , 0.8759 , 0.7148 )
- Injector Comp Batt Volt == Left column (15.99, 15, 14, 13, 12, 11, 10, 8, 6, 6, 6, 6) , right column for multiplier ( 0.7207, 0.7207, 0.8007, 0.903, 1.0166, 1.1416, 1.288, 1.777, 2.8105, 2.8105, 2.8105, 2.8105)

As for the "Fuel Pump Gain Derivative, Integral, Proportional Terms" all set to 0
Fuel Pump voltage table all set to 15
Injector Pressure Drop change with ACT == all set to 40s

Am I missing something?

The car at medium, heavy acceleration and WOT is great with no issue at all.

only thing it can be then is fuel resonances

youll need to put a pulse damper on her

ok can a minor oil leak from Cometic MLS gasket between the cylinder head and block in cylinder #4 on the side of the intake manifold cause this issue?

no idea since the engine needs to be 100% in order to tune it