so, about a month ago i was rear ended. minor fender bender. however truck has been acting up ever since.

i have a 95 f150. 351w 4x4. dual tanks. truck has 85000 miles on it and overall is very good shape. however, all of a sudden (after driving around town during the day fine) i jumped back in to take off and i went to hit the key and i immediately noticed no fuel pump sound. i tried starting anyway and sure enough she wouldn't fire. i tried toggling between tanks and neither tank will prime. however the fuel gauge does go back and fourth for each tank level like normal. there is an audible click when i turn the key to run before ignition but thats all. i have read many many forums and articles on this sight and others and cannot diagnose this situation.

here is what i know and what ive tried so far.

1. checked the fuse, its good
2. i had a brand new relay so i plugged it in, no change (also swapped it with horn just to be sure)
3. checked inertia switch, its in correct position. ( note: i put a test light on it and it is receiving juice out of i believe the green/yellow wire)
4.went back under the hood and checked for corrosion around fuse box.

now here is where it gets really annoying

i unplugged both wiring connections for front and rear to check for corrosion. they still had the factory dielectric grease in em and were super clean. i didn't have a helper so i tried to see if they had power but couldn't do 2 things at once. i plug everything back up, and last minute decide to try one more time and see if i could here the click again when trying to start. and she actually fired right up and idled normal. i let it run for about 5 minutes and then decided to try switching tank, i switch to the front tank and the truck died. i switched back to rear tank and tried to start and it would not.

i know this post is a little long but i wanted to be thorough and hopefully somebody smarter then i am can shed some light before i start taking the tanks down and the pumps out. thank you in advance!

 

Dark Green/Yellow wire is power TO the inertia switch. The output is Red/Yellow.

A diagram that might help:


You can jumper Pins 2 & 6 on the diagnostic port then turn the key to the Run position to keep the fuel pump relay energized. Use a test lamp to verify power is leaving the inertia switch. Might be worth a shot to trip it then reset.

 

thanks for the diagram. i have read in a few places about a test port. what do you mean by that and where would that be? thanks

 

also i forgot to mention i did put my scanner up to it and it is throwing the 542 code i believe it was. the " open circuit in fuel system"

 

Test Port or Point

A pressure test point with a Schrader fitting is in the engine fuel rail to relieve pressure in the fuel system and to measure the injector supply pressure for service and diagnostic work.

 

It's the test port to run the diagnostic tests. Same place you plug the code reader into.

Jumper Pins 2 & 6 as stated previously.

 

Check to make sure the high pressure fuel pump is working on the frame rail, the little red wire can wiggle itself loose.

 

No high pressure fuel pump on the frame rail for a 1995 F-series truck.

 

Is there a high pressure pump on the frame rail of an 84?

 

No, the 460 is not a FI engine in 1984.