my 92 f250 351w A4OD ,was running great then just died during takeoff. I just replaced the upper and lower intake gaskets and trans filter and fluid. Truck was idling and running fine. I drove to the dumpster about 1/4 mile away, put it in park, let it idle while I emptied the trash. Jumped back in, dropped it in drive started off, then it sputtered and died. Would not start back.

Fuel pump would not energize on either tank. (yes it has fuel in the tanks) I pulled it home and started diagnostics. All fuses are good under the hood and in cab. When I turn the key on, neither the ecm nor fuel pump relay click. I have 12vdc on the fuel fuse (both sides) but inside the truck at the selector I only have 1.3vdc coming in from the dist box. I checked the inertia switch and it is down.

I check the spark plug wire but no spark while cranking over. I then swapped relays (same part number) but no joy.

One thing about this truck, the gear shifter is a little loose. Sometimes the starter will not engage until you give it a good shove up further into (P). Could that be the issue? Any way to test for short?

Any help is appreciated here.

 

See if it will run on ether, it's not always easy to physically test for spark.

If you truly have no spark or fuel, likely culprit would be the computer or even bad grounds. The jy is a great source for donor eec's.

 

Need more information.
Does the headlights work?
Dose the Radio work?
Dose the doom light work?
Do the turn signals work?

Maybe a bad Ignition switch.

 

Or the MLPS could be bad or out of alignment. Seems less likely but it is easy to inspect. Will it start in neutral? Checked for codes?

 

He said it cranks. If MLPS was out of alignment it would not crank.

 

Good catch... sounds like a loose connection or failing ignition switch (well maybe failed now). They should be able to trace it out with a multi meter with the ignition cylinder in the run position? Or just drop the column and check out the switch.

Usually when the ignition switch goes bad, it is the tabs holding the 2 halves together getting loose and you can tell pretty easily upon inspection.

 

How many keys on your key ring? I replaced a couple lock cylinders for a similar issue on my '94 F250 gasser. Found out too many keys causes the lock cylinder to wear unevenly to the point it wouldn't actuate the switch properly.