I have a 7.5 gas motor that has been rebuilt. Everything went together well. We have 2 new fuel pumps and the pump on the frame rail is also new with a new filter. New map sensor, new dist., plugs, wires, cap, rotor, coolant temp sensor, -almost evry sensor has been replaced - and new injectors. We just set the timing again and double checked that the plug wires and injector harness were properly hooked up. On start up it runs a little rough, but once it warms up, it only gets worse - it has a skip and seems to be dumping excess fuel into the cylinders. Any ideas??? Thanks

 

Moved to the 1987 - 1996 F150 & Larger F-Series Trucks forum.

 

Have you checked the injectors? Either replaced them or had them tested?

 

yes- they were replaced with new ones

 

I don't see anything about the fuel pressure regulator.

Is there fuel in the vacuum hose?
What pressures do you have at idle and with open throttle?

 

new fuel pressure regulator - no fuel in vaccuum line.
35 lbs at idle - hard to get full throttle because it runs so poorly, but fuel pressure jumps up when given added throttle

 

I wonder if your coil is getting messed up when it gets warm, I've had that happen on an old Honda.

 

I thought of that but the coil is new as well - not that it couldn't be bad- you know how some of these parts are