Another truck won't start thread!

[matt the pilot]

Hey guys I'm new to the board. I have a 2000 Explorer 4dr, 4.0L. A couple weeks ago the truck started acting up. I would have to prime the motor like 3 times for it to actually start up in the morning. Finally, it just stopped working all together. The motor cranks over strong yet I couldn't hear the fuel pump priming the motor when you first turn the key on. SO I thought the fuel pump went out. I pulled the fuel pump out, swapped in a new one, and again, it didn't prime the motor. So I tested the original fuel pump straight to a battery (which I should have done in the first place) and the fuel pump works fine. So this leads me to believe maybe a blown fuse. I have checked all fuses, and all are fine. What about relays? Where would the fuel pump relay be? Or am I missing something here? Is this a common problem or should I Just take it in to the mechanic and have him deal with it? Let me know guys I appreciate any help. Thanks.

 

[Doubt Incarnate]

dont forget to check the collision switch, maybe your fuel filter as well.

any codes?

 

[matt the pilot]

It was the inertia switch. Well that was easy. Thanks for the reply though.

 

[zedsdead]

whats a 'inertia switch' ? im having a problem with my truck, it seems that a couple times in dead winter it doesnt start, will try to crank, but no go, i finally thought it might be the battery bought a new one and nothing..... is there anything with ex's and cold temps? any help would be great....

z+

 

[matt the pilot]

whats a 'inertia switch' ? im having a problem with my truck, it seems that a couple times in dead winter it doesnt start, will try to crank, but no go, i finally thought it might be the battery bought a new one and nothing..... is there anything with ex's and cold temps? any help would be great....

z+

The inertia switch is on the firwall in the passenger foot well. It has two wires going to it. In the event of a collision, it gets knocked in the "off" position so to speak, cutting off the power to the fuel pump. SOMETIMES it can get knocked over if you hit a bump or what not.

 

[marragtop]

When it won't start, turn the key to the ON position, and you should hear the fuel pump prime for a second or 2. If you don't hear that, then your problem is fuel delivery related. If you do hear it run, then your problem is probably spark related.