Forgive my ignorance. I recently bought an 89 pickup and put a rebuilt engine in it. Prior to rebuild it would stall when not giving any gas. My buddy adjusted the screw on the throttle to keep it idled up a little so I could get it home. Since the rebuild it idles fine when cold but when the engine gets up to temp it drops significantly. It does not stall but idles low and bogs down a little. It runs fine and has plenty of power, just idles rough when stopped with the clutch in. I cleaned the throttle body and egr valve and it didn't help. I used a multimeter and checked the tps on the bottom 2 pins and got no reading at all. Does this mean I have a bad tps? If not, where should I go from here?

Thanks