Don't assume that ECU connector pin 6 is the same as frame ground. It is
FI sensor common, and may be "ground" when ECU is plugged in(I don't
know), but without the ECU plugged in pin 6 is certainly not grounded
and may not be true ground even with the ECU present.

First, with both device unplugged, Bentley says measure from pin 4 of
AFM connector to pin 6 of ECU connector. What ohms do you get doing that?

Second, Bentley says with AFM connected and ECU removed, measure between
pin 6 and pin 9, both on the ECU connector. What do you get? This may be
your running problem if outside of expected range.

Mark

neil n wrote:
> Hi all.
>
> Under these conditions:
>
> - grounds between engine and frame cleaned and ok, new braided strap
> between engine and frame
> - battery negative clamp dis-connected, ECU dis-connected
> - VOM probe to new braided engine ground strap or various points on engine
> metal.
> - big brown ground wire in ECU harness re-connected to bare frame metal
> near ECU.   (this made no difference to engine performance)
>
> I should see continuity between pin 4 of AFM plug, ground wire of temp II
> sensor, ground of throttle valve (enrichment) switch, pin 6 of ECU, and
> engine metal or frame correct?
>
> I don't. Measuring between pin 6 of ECU harness and new ground point near
> ECU, I see a huge resistance or infinite Ohms.
> ..........................
>