Lack of fuel @ WOT - E38

[HTMtrSprt]

Was your VVE setup with MAF disabled?

EDIT: just took another look at your VVE. How did you manage to get your VVE airflow reduced by so much at low map values? Like halved in some cases.

The VVE table HAS been set up properly..... this car has a cam in it w/ long tubes - the engine moves less air at low speed and low MAP pressure. It starts and drives flawlessly with computed (speed density) air flow numbers matching the MAF air flow numbers at idle and part throttle cruise with no problems on transitional throttle. The data log shows this as computed total airflow is the same as MAF total airflow, but the ECM seems to be disregarding the computed air flow number and using some sort of backup number as evidenced by the air/cylinder parameter showing half air/cylinder that it should until high speed mode.

[gmh308]

The VVE table HAS been set up properly..... this car has a cam in it w/ long tubes - the engine moves less air at low speed and low MAP pressure. It starts and drives flawlessly with computed (speed density) air flow numbers matching the MAF air flow numbers at idle and part throttle cruise with no problems on transitional throttle. The data log shows this as computed total airflow is the same as MAF total airflow, but the ECM seems to be disregarding the computed air flow number and using some sort of backup number as evidenced by the air/cylinder parameter showing half air/cylinder that it should until high speed mode.

Ok that completes the picture. There are other background factors that GM uses to correct the VVE model. Moving the VVE a considerable amount like you have had to (cam/blower/longtubes etc) can mess the correlation up. Which is why with a lot of S/C apps it is simpler in aftermarket apps just to run 100% MAF from low rpm which bypasses the low speed headaches.

Even aftermarket S/C kit manufacturers that are close to the factory do this.

[gmh308]

Ok that completes the picture. There are other background factors that GM uses to correct the VVE model. Moving the VVE a considerable amount like you have had to (cam/blower/longtubes etc) can mess the correlation up. Which is why with a lot of S/C apps it is simpler in aftermarket apps just to run 100% MAF from low rpm which bypasses the low speed headaches.

Even aftermarket S/C kit manufacturers that are close to the factory do this.

Looks like Ross had added in these VE correction tables in the latest definitions in the Airflow section. "VE Compensation".

Swingtan: these may interest you for MAFLess VVE fine tuning.

[swingtan]

The only problem, is that I'm running the old private Beta COS with the Valet mode.... so no updated calibrations for me :( I'll have a look though.