I recently bought a '91 F-250 4x4. It's got a 351 with a C6 auto. I knew there was an issue with the fuel pump not always coming on, but usually after turning the key two or three times the pump would start up. Last night, after coming home from work, I dropped a load of stuff at one of our outbuildings. Started it up, drove to the other outbuilding and unloaded more stuff. I tried moving it again and it wouldn't start. A couple of times I could hear the pump spinning, but no start. A few times, I heard what sounded like ticking, similar to when the engine's cooling off. Do I have a bad pump, a bad ignition switch or what? I bought this thing so I'd have something to drive while I'm fixing my Chevy.

 

Good way to check is to bridge the DLC connector pump circuit to run the pump continuous. If the pump runs, a pressure and volume check to gauge pump health is a good start point. Being the pump circuit is full time active without a running engine, helps to diagnose power distribution/relay/inertia issues.. Ground the pump terminal only, key on, engine off

 

OK, is that the little box under the hood, right in front of the master cylinder? I'm not sure this will really help. I always turn the key to "on" and listen for the pump before I waste power cranking the engine. BTW, I tried about 4 hours after posting this and it started. The pump works fine once it's running - no issues with driving it other than the "check engine" light and terrible gas mileage.

 

If the exhaust pipe is really black you might remove the vacuum hose from the fuel pressure regulator on the left side of the engine on the fuel rail, if gasoline drips out the regulator diaphram is defective and it is pulling addl gasoline in when not needed and can contribute to hard starting. Just something to check.

 

Thanks. I'm starting to suspect that it's related to charging. I've driven into town a couple of times and it just died on me. When I tried to restart, it cranked very slowly. After a couple of minutes it would start. If I rev it up when I start it to make sure it's charging fully, I don't have problems getting home.