I put an engine in a 1989 Chevrolet 1 ton van (24 passenger school bus) with 350 throttle body. The engine will run as long as I pump the foot feed, it won't idle. I washed the throttle body with a degreaser and water but blew it out as soon as I was done about a month ago. I hear the fuel pump cycle when I turn the key on. There is 12 volts to the injectors, and the injectors pump while the engine is cranking over. I have not tested the fuel pressure as I am not sure of the pressure required. Can you tell me what the fuel pressure would be for this vehicle. Any ideas if the pressure is where it should be?