I bought the truck off the guy that posted above you. It was throwing codes for Cylinder Head Temp Sensor, Crank Angle Sensor, and Fuel Injection Circuit in limp mode.
I replaced the Water temp sensor behind the timing cover which removed that code, then tested and replaced one of the fuel injectors and now its running flawlessly with zero fault codes.
The 2 injector TBI system uses one injector at idle, and uses both under load. I'm not sure what else puts it in limp mode but I know the injector does for sure so I would start there.
I would start with checking the injector resistance because its the easiest test:
unplug the injector harness connector and test the resistance between the two top left pins, then the two top right pins, should be about 1.5 ohms each. if its not, replace it or rebuild the bad one. ~$60 to rebuild and ~$300 new a piece