My father has a '92 pickup and it starts up perfect, no issues, but after driving it for about 5 minutes (allowing the engine to warm up) it will begin to stay at a consistent low speed (as if their is a deadzone between the pedal being 1/4 pushed down and 3/4 of the way). After flooring the gas it will begin to act normal and speed up considerably.

The only error code that is being reported is 43 - No starter signal to the ecu.

A couple of fixes we have tried are as follows
- Replaced fuel tank/pump from spare
- New plugs
- Various throttle bodies from spares
- New TPS and other TPS from spares
- Replaced AFM/VAFM with spare (My father says so atleast)