Fuel Level Sensor ... self-corrected?

[Lindsey]

Long-time lurker, first-time poster.

I have an '05 Yukon SLT, 5.3L with 170,000 miles on it. I bought it at 138,000. I don't have a repair history prior to that, but I have not replaced the fuel pump.

The fuel level sensor had been misbehaving, off-and-on for a year or so. Every once in a while it would give me the low fuel warning when I knew there was plenty of fuel in the tank. It would turn off after driving a few miles. Last week the check engine light came on and stayed on. Estimate to replace the fuel level sensor was obscene, so I decided to wait and do some research. One week later, I was driving off road, hit a bump, the check engine light turned off and the gas gauge suddenly reads the correct level. That was last night, drove it again this morning, so far, so good.

It drives beautifully, no indication that fuel pump is failing, though I know they don't always give warning. Is it possible that something is loose, but the fuel level sensor and pump are fine? What would you do?

 

[TheWhiteDevil]

I would run a few cleaners in the tank to remove any varnish buildup on the sending unit level arm. Its likely to come back

 

[jesse53]

The circuit board on the sensor arm gets gunked up.. I finally installed a pump as mine was stuck on empty, the fuel pump was also getting weak by that time.

 

[treehan77]

Mine tells me fuel low half the time if I'm parked the wrong way in a slight incline, then slowly goes to where it should be. Usually lol. No cleaners have helped that, put about 8000 miles on it since it started at 155k. Someday it'll probably strand me, but oh well

 

[Lindsey]

I took your advice and ran Lucas fuel injector cleaner through it, ran beautifully after that. Since then I've noticed that it seems to drive better when I fill up at BP or Shell rather than places like Marathon or Admiral. I have no idea if there really is a meaningful difference in the quality of fuel ...

Fast forward 6 months. My check engine light came on. Took it to the mechanic, got code P0171, nothing else. Driving OK. Maybe a little sluggish, but barely perceptible. He's thinking oxygen sensor but won't know until he really has time to check it out next week. I last filled up at a Marathon station and it sure does make me wonder. Thinking I might run more fuel injector cleaner through it. Couldn't hurt, could it?

 

[adventurenali92]

We don't have those stations here in cali. But we do have shell. And that's the only place I buy gas from. The other cheaper stations have such crappy gas. I won't buy there anymore. My rig runs so much better with gas from shell. It's cleaner.

 

[retiredsparky]

One subject that is never discussed is the quality of the fuel we put in our vehicles. There are a lot of complaints about small engine fuel systems being ruined by old gas with ethynol.
So I have started wondering about how old some of the different brands of fuel is. If we buy from a station that buys on the spot market (surplus fuel), maybe that fuel has been sitting in a tank farm for a long time. Additives added after being stored for a long time won't fix a substandard fuel. Before ethanol, gas would last for a long time. We have been sold a bill of goods by the petroleum industry and the fed's.

 

[Lindsey]

So one bottle of Lucas, half a tank of Shell gas and a mile later the check engine light shut off and performance improved.

I think I'm a believer ...

 

[drakon543]

I used to run whatever additives that were on sale for whatever i wanted to use them on. I first used lucas on a old truck i had with a noisy bottom end so i tried lucas oil additive. I never heard a peep after that for almost a year before i sold it. After that i used the fuel cleaner in a free ****** i picked up. I did all the normal with that car but it would still buck and shake with the constant missfires. After 2 tanks of lucas it ran perfect. It was alot better after the first tank but the second tank definitely finished it up. So a few other boring stories later and now you have my garage with lucas additives sitting on my shelf just waiting to be used.