hey i'm new to the forums i just bought a 93 b2600 4x4 of my father. we put a rebuilt motor in it a couple weeks ago that was sitting around in buddys garage so we had to change most of the sensors on it cause they were dirty and stuff. anyway when we got it in and running on start up it revs really high so dad unplugged a sensor on the top of the intake its a square box bolted on the top of it. it will start and run fine with it unplugged and u can plug it back in i think he said once its warmed up and it doesnt rev up. but if its plugged in when u first start the truck it revs really high. any one know what the problem might be?i think he changed that little box with another one and still has the problem. i drive it daily with it unplugged but i'm sure it probably should be plugged in.