What does the ECU do to allow the approprate A/F to occur when it references this table. What does it look at in .bin other than that table?

I am in OL idle, synch idle, and have BLMs as desired 124-132 throughout when CL cruising(whats up). That above table is set currently at about 13.8/1 for a fully warmed engine(190F) at 30-35-40 vac and 700-1000 rpms. Ethanol fuel. Idle is stable at 800-850 rpms commanded to 750, zero IAC counts, and sitting on throttle stop screw(i believe). EBL'd.


I just repaired my WB(replaced sensor again) moving it back a foot or so in exhaust stream and calibrated it initially and then again 3 days later. I am seeing 17.0/1 at idle open loop? no ext leaks that I can see(double checked).

 

The only modification to the Open Loop AFR table is choke enrichment. Which is decayed out rather quickly. When in idle there is a lean limit check. This makes sure that the commanded idle AFR is as rich as the limit (not leaner).

The EBL output file has a column 'AFR' as the commanded AFR. Then the column 'WB' for the wb reported AFR.

RBob.

 

Is there a possible explanation for my idleing at 17.0/1 considering the WB sensor is new and properly calibrated? Is the above table the only one to consider to regulate A/F at idle?

Cruise A/F is right at 14.3 to 14.7. DE and Highway enlean is disabled.

 

If the AFR at idle was truely 17.0/1, I don't believe the engine would be running.

The reported AFR of 17 may be from the cam overlap, or a tiny exhaust leak.

RBob.

 

OK... Maybe that is it. The WB reads 02 content only not A/F ratio so the overlap or ext leak may be picked up at the sensor. I will experiment a bit and up the idle rpm and see if the mix enrichens. We just had the ext apart adding an alternative WB bung so ext leaks are improbable. header to manifold is clean.

If I were running CL at idle I would expect the BLMs to rise as the NB attempts to see stoich or 14.3. I might flip to CL idle to take a look as well.

I thought maybe something in my tune was lacking.

One thing i purposedly failed to mention was my BPC is fudged to get my VE table 2 under 100 around 3200 rpms 40-75 MAP. I was thinking the BPC used had an effect on the outcome of real A/F in that above table as opposed to what is in that table for value.

Actually car has never run better than this past week.