Hi Harvey,

If you want to verify the amm is conveying the airflow information, read the output voltage back to the ECU. It should run about 2.5-2.75V thereabouts when idling and up to 4-5V when revved up. With ignition on and no airflow it should be around 1.5-1.7V. I figure you have the book if you traced the wiring, so I won't fetch mine and read out pin numbers.

Other inputs to the ECU that govern injector duration are temp sensor (read at ECU- should be less than 0.2V when warmed up.), cold start enrichment (pin 4 I think looks at starter solenoid), and to a lesser extent the lambda sond.

Don't forget the stuff the computer can't control, like a stuck fuel pressure regulator or blocked return line. The tank and fuel delivery must have been a custom arrangement for your sawmill.

Regards and best of luck.
--
Art Benstein near Baltimore