QuestionQUESTION: I have a 1986 F-150 with a 302 (5.0)EFI engine and auto trans.. I ran out of fuel, but can not get engine to restart. I have poured at least 6-7 gal. of fuel in tank. Chilton manual I have mentions needing 10-13 gal. if you replace intank fuel pumps, but no mention if you replace exteral pump on frame or anything about what to do (trouble shooting) and if you run out of fuel. My question is what is the procedure to restart this engine once you have ran it out of fuel? THANK YOU for your time and concideration.
ANSWER: Fuel pressure should be about 45 psi
Do you hear the fuel pump running when the key is first turned on? It should run for 2-3 seconds in whichever tank you are switched to.
There shouldn't be a high pressure pump on the frame. just a switching valve.
older models had a low pressure or "primer" in the tank and a high pressure pump on the frame
if you hear the pump, but have no pressure, check for a plugged filter in the switching valve
Some models did not have a filter. If the bottom cup of the selector valve is 3-4" deep, it does not have a filter. If it's 2" deep it does have a filter from the factory. Some technicians will just replace the O ring and leave the filter out. (They came that way from the factory in 1987).
this should give you a direction to go
Let me know what you find
---------- FOLLOW-UP ----------
QUESTION: The switching valve does what? I only have one fuel tank. When key is turned on, what I thought to be high pressure pump makes noise and vibates like it's a pump. If I turn engine over with pressure release pushed in, I imediatly get a great supply of gas to that point. I know when I turn key on if I touch the wiring for fuel injectors (using a test light), the light lights up on any I touch. Plugs seem to have fire, but I wonder if they foulout easily. Of course, now I even question running out of fuel, I just assumed... It did have a little surge thing (varience in idle) at times prior to this, but I paid it no mind as I haven't had the vehicle vary long or driven it much. What would cause that a sensor? Could that lead to it just die and not restart? Thank you again for your time and consideration.
AnswerWell, you found the critter that is giving you the greif.
If the truck is high mileage, I would suspect the timing chain is too loose.
To check this, remove the distributor cap and fit a socket onto the crank bolt (you may need 2 people to do this)
Turn the bolt clockwise until rotor starts to move. At this point, put a reference mark on the crankshaft pulley. take note of the rotor position and start to turn the crankshaft bolt counter clockwise until rotor starts to move again. check your crankshaft pulley reference mark, It should be no more than 1/4 " away, More than that and the chain has sufficent slack to jump a tooth or more. Another possibilitie is the spring pin on the bottom of the distributor may have sheared
