HELP! Intermittent power to fuel pump 95 Sport Trac

[JHolben]

My 95 exp Sport Trac has been giving me fits. I replaced the fuel pump, because of non-starting due to lack of fuel, about 3000 miles back. Since that time, (after starting and running with NO problems for a couple of months), everythings fine, then all of sudden, out of the blue, on several occasions it wouldn't start due to no power to the fuel pump (assumed due to non-starting and no sound from the fuel pump when the key is turned) . Then *miracle occurs* , it would start and run just fine for a few days, then *Gremlin reappears*, no power to fuel pump. fuses fine, PCM ok, ...then without doing anything other than repeated attempts to start it, *another miracle occurs* and it starts. This time however is different, no amount of "attempts" are successful. I have run completely out of "miracles". Ideas anyone? P.S. please excuse rambling nature of this post. I am rushing to post this.

 

[Runnin'OnEmpty]

Try these two things: Push the reset button on the inertial FP shut-off switch and see if it starts. Then swap out the FP relay with a similiar one (possibly the A/C relay?) and see what that does.

Could be that you're not getting full voltage to the FP causing the erratic starting. Relays have contact points inside that do wear out over time. As do the inertial switches.

 

[shadowless127]

I'm gonna guess it's something with the Inertia Switch. Make sure the plug is tight into the switch. Also may want to pull the switch out and clean the connections.

 

[partsman48210]

did you test for power at the pump? Also remember your'e going to need a helper to turn the key on for you while you're testing. I youre turning the key on and then have to run around to test for power, by the time you get there you'll have no power. the power only stays on long enough to prime the lines up to pressure. It will stay on while cranking though.

If you've done this then I suggest you work backwards from the pump until you find power. A wiring diagram helps here.

I'll see if I have a diagram or maybe someone else here has one.

Also make sure you have ground at every place you test for power

 

[partsman48210]

here i just found this

 

[JHolben]

Thanks everyone for your help/advice.. I'll get back on this post once I have success and/or find out what the problem was. Muchos Gracias Mi Amigos