This is common, the pickup tube off the fuel sending unit is made of rubber and disintegrates over time and the bottom rots off and falls to the bottom of the tank...the whole tube doesn't fall off, just enough that the truck will run out of fuel at 1/4 tank.
The fix: Cut a length of fuel hose that will fit over the pickup tube on the sending unit. Make sure the hose will reach the bottom of the tank. Not too long that it will turn back up like a J though, try to have it sit right at the bottom. Also, the end of the hose into a V so it won't suck itself to the bottom of the tank.
I have removed mine and this is what I believe has been done. See attached images:
First image shows the pickup and the second a close up of a part on the pickup line. Is this round thing above the attached fuel line a check valve? If so it must not work without the old foot at end of pick-up line as I see no way this prevents fuel from leaking back into tank since fuel does not flow thru the spring loaded valve. Is this anything to be concerned with?
That setup you have is factory, the '83s & '84s didn't have the cone of failure on them.
As I understand that check valve it allows the tank to continue to feed fuel should the pickup at the bottom become plugged or gelled.
__________________ -Niles 1985 F-250 Lariat Ex-Cab 4x4, 7.3 IDI,ZF5
1986 F-250 Lariat Ex-Cab 4x2 6.9 IDI C6
1992 F350 CC dually 7.3L IDI, E40D Sold!
Blaming the Prince of Fools should not blind anyone to the vast confederacy of fools that made him their Prince!
one more thing this thread needs - how to add an electric fuel pump to solve hard starting from air intrusion problems. copied from another post where i just answered this common question
you are able to have both the electric and mechanical pumps installed, but ONLY if you have the electric set up so it only runs for a moment to prime the system, then turns off and lets the mechanical do all the work. thats how i have mine wired.
if you want to run the electric all the time, you must bypass the mechanical pump, or you run the risk of a pinhole leak in the mechanical allowing the fuel to be pumped into the crankcase, dilute your oil, and blow your engine.
now, here's a standard relay
so i'll give you some guidance here on how to wire it up for either way you want to run your pump. 1) pump always on with key on - must bypass mechanical pump
30 - fused battery power. i suggest connecting to the battery side of the starter solenoid, through a 10a fuse or circuit breaker
85 - ground - connect to a screw in the nearby sheet metal
86 - connect to FSS wire on top of IP.
87 - to pump
87a - not used
or you have an alternative wiring plan that i used. my e-pump is wired to run anytime the glowplugs are lit plus anytime i hold a pushbutton in the cab
2) pump runs momentary and may push fuel through mechanical pump
pushbutton will be a simple 2 wire unit which is on when pressed. this is the most common style and in electrical speak is SPNO (single pole normally open). it must be rated to carry the full load of the pump, which is usually less than 10a. that means you can't use that super-tiny one rated at 3a.
30 - to pump
85 - ground
86 - to glow plugs. i connected to the plugs side of the GP controller.
87 - fused battery power, as described above. also to one side of the pushbutton
87a - to the other side of the pushbutton
note that the pushbutton can be left out of this wiring plan, but is very helpful to have in the event you stall from air intrusion while running, change a fuel filter on a hot engine, or for some other reason need to run the pump at any other time than cold-start priming of the system. i added the pushbutton to mine after air intrusion got me after sitting at a store for half an hour and i had to crank on it for a long while.
for either plan, i recommend using 14ga wire for everything the diagram labels "high power", and 18ga for the relay coil wires, as they carry minimal power.
in my personal opinion, this second plan gets the best of both worlds. when i did this to mine, the mechanical pump was a month old and i didn't want to screw with it, so i read the warnings about having both pumps together (fuel in oil, etc) and decided to build it this way. its worked perfect for me for well over a year so far.
my van, 87 e350, 6.9 NA, c6, 3.55s with a powertrax locker and 225/70r19.5 michelin tires. built out with toolboxes and onboard 120v power and compressed air powered by twin 3g alternators
This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. Ford® is a registered trademark of the Ford Motor Company.