Solved! Low rpm and sudden stall

[grtescpa]

After reading into all possible solutions the problem turned out to be very simple. The low idle adjustment screw had a detent worn into it from the lever. (From all the up and down of the throttle in 75k miles. ) It was very hard to see because of its location at the rear of the injector pump. A 10mm box wrench is needed to loosen the lock nut. It helps to have someone hold the throttle open so you can adjust the bolt. I did mine with the engine off and a good guess. The book says for automatics to set it to 1000 rpm. It should be 750 to 800 with a/c on and in drive. For those who suspect a bad overflow valve just pinch off your fuel return line. If the rpm's come up you have a bad valve. Mine was ok.