AFD ProFlex E85 Commander Journey w/ GT350

[mmakam2]

reset the codes and it came back again, I'm on the stock tune with e70 in the tank.

watching the AFRS, it definitely is leaning out under throttle but at idle the afr is perfect at 14ish.

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[JAJ]

Clearing the code and watching the AFR's won't tell you anything useful, unfortunately. The ECU has two different ways to correct a lean condition - fast and slow. Fast is just that and fixes any errors within a few turns of the crank - which means your dash readout will show "normal" AFR's even if there's an error. If the fast system continues to operate in fix-it mode for long enough, the slow system gradually takes over and does the fixing. Your dash readout will still say normal. If the slow system operates long enough, the ECU gets fed up with fixing things and throws a code. If you clear the code without fixing the cause of the problem, then the code comes back fairly quickly because the fault condition that set it is still present.

The correct AFR (Lambda) for E85 is around 9.8, not 14. The aftermarket device is fooling the ECU by keeping the injectors open longer than the ECU is commanding - the ECU is commanding enough injection time to get an AFR of 14 and the time extension device is delivering enough fuel to get 9.8 in the cylinder. If the ECU is throwing a lean code, then the injectors are not open quite long enough. Or the ethanol sensor is out of spec.

 

[mmakam2]

that's confusing because the system only sits between the injector harness to adjust pulse width.

Doesn't the Afr ratio on the dash give a read out directly from the wideband?

 

[mmakam2]

I tried a kam reset with the DTC clear this time, and the lean code hasn't come back yet .

 

[mmakam2]

Clearing the code and watching the AFR's won't tell you anything useful, unfortunately. The ECU has two different ways to correct a lean condition - fast and slow. Fast is just that and fixes any errors within a few turns of the crank - which means your dash readout will show "normal" AFR's even if there's an error. If the fast system continues to operate in fix-it mode for long enough, the slow system gradually takes over and does the fixing. Your dash readout will still say normal. If the slow system operates long enough, the ECU gets fed up with fixing things and throws a code. If you clear the code without fixing the cause of the problem, then the code comes back fairly quickly because the fault condition that set it is still present.

The correct AFR (Lambda) for E85 is around 9.8, not 14. The aftermarket device is fooling the ECU by keeping the injectors open longer than the ECU is commanding - the ECU is commanding enough injection time to get an AFR of 14 and the time extension device is delivering enough fuel to get 9.8 in the cylinder. If the ECU is throwing a lean code, then the injectors are not open quite long enough. Or the ethanol sensor is out of spec.

Are you saying the AFR is calculated by the MAF / the injector pulse width not the wideband output?

 

[mmakam2]

After the KAM reset things have improved significantly. Tip in power is better, off idle power, and response is improved. Also AFR on the dash isn't going as high as before. I think the ECU just needed to relearn fuel trims.

Edit: spoke too soon, after another 30min same code is back. It's possible the 2019 MY has a different calibration than the rest which is why the system isn't working good for me.

 

[Mjc1241]

I have never thrown a lean code on mine. Maybe there is something of a different calibration for 2019 models.

 

[lightrules]

how are you guys resetting the kam and checking for lean codes?

 

[Mjc1241]

Did you recheck your injector connections?

 

[lightrules]

Did you recheck your injector connections?

I would think check engine light would come on per the instructions for the proflex. all clear on my end.

 

[mmakam2]

I rechecked all injector connections, and content sensor connections. There are no misfires, if one of the injectors wasn't connected id be getting a misfire.

 

[mmakam2]

I would think check engine light would come on per the instructions for the proflex. all clear on my end.

When I ran the car with the module unplugged (with 93 still in the tank), per the instructions I had no CELs.

Only got the lean code after day 2 driving the car around with E70 in the tank.

 

[JAJ]

Are you saying the AFR is calculated by the MAF / the injector pulse width not the wideband output?

Yes. Essentially, the ECU maps fuel to the MAF signal, and because it knows the fuel pressure and injector flow rates, it delivers a remarkably accurate fuel load. The wideband is just there for to fine-tune the system by feeding into the short-term and long-term fuel trims. In normal operation the trims stay inside a range that's set by the OEM's measured manufacturing tolerances. If the trims move outside the normal range for long enough, you get a code.

 

[mmakam2]

Yes. Essentially, the ECU maps fuel to the MAF signal, and because it knows the fuel pressure and injector flow rates, it delivers a remarkably accurate fuel load. The wideband is just there for to fine-tune the system by feeding into the short-term and long-term fuel trims. In normal operation the trims stay inside a range that's set by the OEM's measured manufacturing tolerances. If the trims move outside the normal range for long enough, you get a code.

Very interesting, thanks for this, do you know which parameter in the SCT logging software is true lambda?

 

[mmakam2]

I'm thinking its one of these..

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