I've got a 1996 7.3 with some type of fuel issue. I don't drive the truck much so of late I've only been using the front tank. I went to fill it up yesterday, and while doing that I flipped the switch to the rear tank. The truck was off, key switch on. When I flipped it the fuel gauge went way past full, as far as it can physically go. I switched back to the front tank, no change. I figured it was a 30 year old gauge issue, turned the key off, hung the nozzle up and left. Luckily the gas station is close to my house. about a 1/4 mile from my drive way the truck started losing power. I coasted in the driveway (trying not to take out the fence because the lack of power steering kinda snuck up on me!). My hopeful theory is that the tank selector valve puked and is stuck on the rear tank and I just ran it dry. Not remembering how much was in it caused the whole issue in the first place. But, I'm not sure how that relates to the fuel gauging burying itself to the right. Does anyone have any ideas? I'm not really a mechanic, but somewhat capable.
Old F250 Fuel Issue
- Thread starter SDM
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May not be a connection but the CPS on those can cause some issues. When you said losing power that is one thing the CPS can cause. Also, it could be a fuel pump issue also.
www.autocarneed.com
5 Symptoms To Detect CPS Failure On 7.3 Powerstroke
The 7.3 Powerstroke CPS failure symptoms include engine stalling, hard start, increased fuel consumption, engine not starting
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chevytaHOE5674
Well-known member
Those tank selector valves give all kinds of problems. Sucking from one tank and returning to the other, getting stuck between tanks and sucking from nowhere, leaking air, etc.
When I had an OBS Ford I ditched they electric valve and had 2 manual valves on the floor between the seat and door.
When I had an OBS Ford I ditched they electric valve and had 2 manual valves on the floor between the seat and door.
I knew there were indications, but I was going to have to look them up, thank you.
I read this afternoon that the gauge going past full is a sign of an open circuit. I'm hoping it's a fuse. But the motor still ran out of fuel so that may not completely fix the issue and that would raise the question of why did the fuse blow.
Caustic Burno
Well-known member
wbvs58
Well-known member
I have had fuel gauges go right off the scale with a poor ground connection.
Ken
Ken
I can't tell you how many of those old Fords I've owned with the dual fuel tanks (still have a 96 and 97 with them) and I've learned to never move the selector switch unless the truck is running. They can do some weird stuff if you do so while the truck is off.
I order just about all of my 7.3 parts from here: https://www.dieselorings.com/ Good people.
I keep a spare CPS in the glovebox of each truck, along with a 10mm socket and a flathead screwdriver to change it. Your truck has a mechanical fuel pump in the engine valley, so no electric pump to prime with. First thing I'd do is cut the ignition switch on and then switch back to the front tank. If after a little cranking it doesn't start, then I'd pop the cover off of fuel filter and see if the bowl is full, then go from there.
The fuel gauge is switched between tanks by the selector switch, so the fact that your gauges went haywire at the same time this happened leads me to believe your issue is either in the electric switch on the dash or the selector valve on the frame - I'm betting the latter.
Best of luck!
I order just about all of my 7.3 parts from here: https://www.dieselorings.com/ Good people.
I keep a spare CPS in the glovebox of each truck, along with a 10mm socket and a flathead screwdriver to change it. Your truck has a mechanical fuel pump in the engine valley, so no electric pump to prime with. First thing I'd do is cut the ignition switch on and then switch back to the front tank. If after a little cranking it doesn't start, then I'd pop the cover off of fuel filter and see if the bowl is full, then go from there.
The fuel gauge is switched between tanks by the selector switch, so the fact that your gauges went haywire at the same time this happened leads me to believe your issue is either in the electric switch on the dash or the selector valve on the frame - I'm betting the latter.
Best of luck!
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Well, it wasn't a fuse. Found a couple that were blown. One for trailer lights the other for "dash gauges" or some such generic description in what I saw online. If I can catch a cool(er) day I'm going to switch out that valve and see if that's the issue. If not it'll have to go to a real mechanic.
