rh93f150

I have a 93 F150, dual tanks, 160k miles. Last weekend we were off road to a fishing pond- dirt trail, some mudholes. About 2 hours later when we were leaving the truck would not start on the rear tank (it was 3/4 full and had just switched to it earlier that day and had driven there on it). It started up on the front tank that luckily still had just under 1/4 tank to get us out of the woods. No prior indicator of any issues. Does anyone know if this would be the fuel pump or some kind of switch/ wiring issue? If it is running and I switch to rear, it goes dead. I tried a few days later and same result. I did just have the fuel filter changed last month & other tune up items & tranny rebuilt. I have owned it just over 1 yr so do not have full mechanical history.

bjafeman

Sounds like you may have knocked a wire loose or something has shorted out. Check for engine error codes. Wouldn't be surprised if there's a bad ground or something like that...or the pump was just waiting to get one last mud hole session before it died. Probably a wiring thing though.

If you don't have any error codes, check for power to the pump at the relay then the pump. If you've got power at the pump then you may have a bad pump, which means dropping the tank. Someone who has had this happen to them might chime in with something different; I'm kind of guessing.

Fast Hampster

If fuel gauge doesn't read anything while switched to rear tank, than probably Bjafeman is right and it's about fuel pump wiring. Connector is located on the top of rear tank facing towards front of the truck .

techrep

iTrader: (1)

My rear tank stopped working @ 143K had a 94 flare side. it would read fuel and when switched to that tank it would transfer fuel to the front tank. don't drop the tank if your gonna replace the pump ... pull the bed off I thought it was easier. good luck.

rh93f150

thanks guys-- the fuel gauge still works & changes when I switch tanks. Sounds like it could be a fuel pump though which will not be an easy change.

kooly1

^^^Not super duper hard.

Josh 94 F150

stiffen the gas you have left from the rear tank to the front. use the front tank and forget about the back

bjafeman

The wires going to the pump(s) aren't too hard to access. It would be worth it to see if the pump is getting power next time you're under there. Usually a reasonably easy fix if power to the pump is the problem.

I know it's easy to access the power wires just to make sure it's getting power b/c I've done it on my truck. My back tank started acting up too. Mine - probably like yours - WAS getting power and was working poorly for some other reason. Like Josh 94 said; at least I think it's what he meant to say; siphon out the gas (or don't) and forget about it.

Responsible people might choose otherwise, but it's hard not to be lazy if you don't have a check valve/cross filling problem and your other tank works fine.

Little Bill

I had the same problem once. It turned out to be a wire that had come loose from the tank selector switch. There just wasn't any juice getting to the rear pump. I've also been told that it's fairly common for the switches to go bad. Just thought I'd throw in another possibility.

rh93f150

thanks Bill...I will try to check that possibility out this weekend. Luckily this is my weekend warrior, not my everyday driver.