LBZ: Fuel gauge issue

[Dozerboy]

I'm not driving my truck very much anymore. The other day I started it the first time in 6 weeks. After starting it the fuel gauge will read empty with the low fuel light on for a bit then the fuel gauge will slowly start to go up after 5 mins or so. Its only done twice that I can think of. I always park it with a full tank. I'm going to check the voltage with EFI next time I'm in town. Not sure if LBZs have stepper motor issues like the older ones or not. Don't really want to have to drop the tank neither since I would have to pump all the fuel out. I need to get it fixed before Xmas or my wife would kill me if we ran out traveling.

Any ideas? Thanks

 

[Dozerboy]

Well EFI was showing that the fuel tank level was 0%. So I guessing its the sending unit? It doesn't act up all the time, but pretty regularly now. It doesn't seem like like the fuel gauge start "reading right" until I start to drive. I surprised that if its the sending unit it hasn't just gone bad and read empty all the time.

 

[Harbin_22]

We always take the beds off chevys for fuel pumps. A lot easier then dropping the tank. Sounds like a sender but you might clean all your grounds.

 

[coldLBZ]

Bump

It looks like I'm having a similar issue. I took the truck for a drive today for the first time in 2 months. About 1.5 hrs into the drive I watched my fuel gauge drop to E and the fuel light came on. I have actually about 3/4 of a tank. I didn't get a low fuel message on the DIC, and the amount of fuel used is still close. The fuel range reads "---".
All of my other gauges are still working, and everything else in the DIC seems normal. I read on here that if it's the stepper motor for the gauge the low fuel light won't come on. Could it be the sender? Thanks.

 

[Duramax5]

Sub'd, having similar issues

 

[Hoosier]

The LBZ we have on the farm has been doing this for about two years now. We've just dealt with it:roflmao: Too lazy/many other things to do.

 

[jlawles2]

Did you get this fixed?

There is a connector under the fuse block that contains the connection between the sending unit and the BCM. When I had a bad connection causing my tank to read E, this is where the issue was.

Could be a loose connector.

 

[Dozerboy]

Forgot to update this.

I drove my to work for a week and it started working fine. Never acted up at all on our trip and I haven't had a problem since. It has been sitting for 2-3 weeks and my wife drove it the other day and it worked fine she said.

coldlbz
I was getting a low fuel message at start up so I would say its the stepper motor.

 

[coldLBZ]

Bump

It looks like I'm having a similar issue. I took the truck for a drive today for the first time in 2 months. About 1.5 hrs into the drive I watched my fuel gauge drop to E and the fuel light came on. I have actually about 3/4 of a tank. I didn't get a low fuel message on the DIC, and the amount of fuel used is still close. The fuel range reads "---".
All of my other gauges are still working, and everything else in the DIC seems normal. I read on here that if it's the stepper motor for the gauge the low fuel light won't come on. Could it be the sender? Thanks.

Bump

My DIC now says "Fuel Level Low"

 

[jlawles2]

I would get under it and ohm the sending unit. I do not remember the readings. If the sending unit ohms good, it could be the non sealed connector under the fuse block. Corrosion in the connector or a loose connector will cause both empty fuel reading and the low fuel warning.