I am going to guess that it relates to what the ECU thinks the AFM is
doing. Is there a damaged pin in the harness connector for the AFM?

There are 2 things in the AFM, an intake air temp sender and the intake
air quantity meter.

Many times I have seen a Digifant start and idle with the AFM not
connected to the harness due to a slight oversight. No power and bogs
right off idle.

Mark

John Bange wrote:
> So after a couple hours part-swapping and generally diagnosing, I've
> come up with the following:
> Fuel delivery: OK
> Timing: OK
> ECU: OK
> Air flow meter: OK
> Cat: OK
>
> Driving up and down the street clearly shows when the problem shows
> up. When the idle switch is engaged the engine runs and idles just
> fine. The second the idle switch is disengaged, wheezing, coughing,
> and associated engine melodramatics. So what does the ECU ignore at
> idle that might cause? Too tired to continue today. Tomorrow the
> multimeter comes out and the wiring harness and sensors get tested.
>
> --
> John Bange
> '90 Vanagon - "Lastwagen"
> '90 Vanagon GL - "Wiesel"
>
>
>