Truck Forums - '89 cheyenne stalling problem

I’ve been driving the same ’89 Chevrolet Cheyenne as my every-day work truck for the past ten years. Over the years I’ve rebuilt the engine and done all the required maintenance and it’s remained essentially stock except for removing the catalytic converter and blocking off the EGR. It is 305 cubic inch, 5-speed manual, throttle body injection and computer controlled with ODB1.
In the last year or so I can not get it to idle once it’s warm. The truck starts great and will idle for hours as long as I don’t drive it. As soon as I drive it, the engine will not return to idle but will stall. Very rarely, the engine will return to a good idle and will not stall. No trouble codes except for code 32 which is EGR.
I put in a new idle air control (IAC). I’ve also recently installed new TPS and MAP sensors, PCV, fuel filter and alternator. All parts are from Napa. Timing is TDC as per the emissions label. I’ve read through the “rough, unstable, or incorrect idle, stalling” section in the factory service manual probably 45 times. This one is driving me crazy…PLEASE HELP.
Thanks very much!!!