manson13666

hey,... im try'n to fix a buddys 88 f350. cranks but no start. i can not hear the fule pump ingauge and charge the system when i turn key on engine off. i try to purge the line and their is no pressure. now its a dule tank truck, so im assumeing that theirs 2 in tank fule pumps (didnt see a external one...just some crazy filter thing?), neither of wich ingauge with koeo. i can understand if one pump died, but both...i dont think so? so im thinking maybe they both connect somewhere and the power, or ground to that is cut. i tryed jumping what i thought was the fulepump relay for it, drivers side firewall?, but with no luck. also, that relay i followed the power wire till it dissapeared into somthing in the bed and it had power to that point, i evin fixed a fuse, 2 bad splices, and a bad ground up to that point... any ideas? i need to get this fixed bad.

 

outback_ute

What you did sounds reasonable, are there any removeable panels in the bed or underneath to keep following the wire? Can you get hold of a wiring diagram or workshop manual?

89F150

Check to see if the inertia switch is a problem. I think you'll find it under the panels near your feet. I'm not sure which side. I'll try to find out where for you. Try to jump it, if you can find it, to see if the pumps run when the ignitions turned on.

manson13666

hey, i already checked the inertia switch, today i mannaged to "aquire" a shop manual both about 3" thick for it, didnt have time to check more stuff tho. i heard all sorts of stuff about the fule pumps on these, like theirs one on the rail, 2 in the tanks, or 2 in tanks and one on rail. where are they??? and what is that big black cylinder with all the fule lines go'n threw it? fule filter/valve?

89F150

I think that black cylinder is a diverter valve. These trucks have 3 fuel pumps 1 low press pump in each tank and the high press pump on the frame rail just forward of the diverter valve.