With 1983 Toyota Pickup, assuming engine compression is good (since the engine has been rebuilt) we have to recommend you find a carburetor expert to tune your Toyota's carburetor.
There are 2 (visible) screws on the carburetor for idle/speed adjustment. The screw that is screwed in furthest is for your Toyota pickup trucks idle speed. The other screw is for the high idle cam speed. If you have idle speed problems, you should start here. We also recommend checking carefully for any vacuum leaks around the carburetor, a stuck carburetor float, and air/fuel mixture proper adjustment.
The air/fuel mixture screw is hidden. Toyota does not want owners tampering with it. The idle/air mixture screw is located on the passenger side of the carb and has a small metal cover about the size of a pencil eraser. It must be drilled out in order to gain access to the screw. You may then adjust the air fuel mixture. Turn clockwise to lean the air fuel mixture, and counter clockwise to richen it.
Typically factory adjustment is the air/fuel mixture screw turned all the way in and then backed out 2 and 1/2 turns.
