I replaced my water pump on my 1977 F100 351W T/L 4sp a couple of weeks ago and had the same problem as another member had with a broke bolt. I got it put back togeather and it will not start. I know I have fuel to the carb. This thing ran fine before the W/P change out. My question is this. The after market gauge I put in years ago started showing 180 temp when the key was turned on. When the motor was up to temp, I checked it with a temp gun. The gun would showed 175 and the gauge would be peged..I put a new sender in from a new guage and hooked up to the old guage.Turn the key on the guage went to zero. Disconnect the sender, turn the key on and the guage pegs out? The motor will not fire up even with starting fluid. So is the old guage the problem as to why it will not start? Is it grounding the ignition? Any help would be apprciated thanks Emmett