I have a 96 F250 351W/auto 4x4 with just over 46k on it. It is used for pulling a landscape trailer full of equipment (about 3500-4000lbs total) mostly around town.
The truck doesn't get much highway use except for a 40 mile round trip every other week (without the trailer).
The truck starts fine the first time in the morning and I will drive a couple miles to the first customer. The truck could sit for anywhere from 1/2 hour to 3 hours before starting it again but that's when the problem starts. The truck will take anywhere from 1 to 3 tries to start. It cranks fine and sounds like it might start but doesn't. Turn the key again and if the truck starts it blows smoke. The smoke (to me) smells and looks like a problem with too much fuel.
The oil was changed 2500 miles ago and the truck does not need any so I feel confident the smoke has nothing to do with burning oil. Also the truck has recent spark plugs, cap and rotor.
Any feedback on this problem would be appreciated. I am wondering if it is some sort of intermittant injector problem. Any ideas?
I think I just fixed this prob on my 92 4.9 f-150. The throttle body gasket had sucked in. Looks like poor design to me. The 351 throttle body should be identical with larger bores. Try spraying carb cleaner where the throttle body meets the intake. Should make rpm jump. Sure did on mine.
Check out in the "Fuel Injection, Carburation and Fuel System" forum on this website where I posted a (long winded!) response to "92 F150 Fuel Injectors" on 10/12. I had a similar problem with my 95 F250 with 351W. It was a combination of bad fuel pressure regulator and leaking fuel injectors.
A friend of mine with a 94 F250 had the same problem also caused by leaking fuel injectors, but we both had about 110,000 miles on our engines compared to your relatively low mileage. The light truck fleet where I work at is exclusively Ford (holds up the best in mining environment!) and the mechanics say that they often start seeing the leaking injectors on them around 100,000 miles too. The only things these Fords don't hold up to is open range cattle...
Thanks for the information. I read your response to "92 F150 Fuel Injectors". I think my next step is going to be a fuel pressure check and maybe pulling the spark plugs to see if any are getting wet with fuel. After that possibly rebuilding or replacing the injectors.