2000 Express Van Fuel Gauge Issue

[Scotw4]

Chevy Express Van fuel guage is iradic in displaying fuel on board.
At full tank gauge indicates properly. At about 1/2 a tank the gauge will function iradic-showing full tank or showing 1/8 of a tank or moving back and forth between the two. The van has just over 100K miles. Any ideas on how o trouble shoot this issue. Thanks

[MT-2500]

Welcome to AF
Points to tank sending unit.
They work off of a built in resistor.
When it is acting up take a ohm reading on tank unit and see it it is erractic.
Check all wiring and grounds.
And also the 4 wire plugin to tank fuel pump and gauge at transmission crossmember.
MT

[Scotw4]

What might be the cost in replacing the tank sending unit if it indeed is the problem?

[MT-2500]

In answer to your PM it is best to keep questions in your post.
It needs checked out and tested for bad wiring or fuel tank sending unit before throwing parts at it.
On cost check parts place or dealer.
The fuel tank will have to come off to replace tank unit.
And with a 100K you might want to replace the fuel pump at same time.
The fuel pump module comes with a new pump and sensing unit.
And if replacing fuel pump only use a AC-Delco/Delphi PUMP.
MT

[toptech69]

I Agree ONLY use the ac delco pump, also do the fuel filter. Chevron fuel additive is good at preventing sender/sensor problems in the future.

[automps]

Originally Posted by Scotw4

Chevy Express Van fuel guage is iradic in displaying fuel on board.
At full tank gauge indicates properly. At about 1/2 a tank the gauge will function iradic-showing full tank or showing 1/8 of a tank or moving back and forth between the two. The van has just over 100K miles. Any ideas on how o trouble shoot this issue. Thanks

Hello, My 1999 Chevy express is doing the same thing ! I replace the sending unit STILL Does the same thing . Test the gauge with snap on scanner , command the gauge to fill ,goes up and back down . Iam thinking the gauge is screwed up . All wiring sames to be ok . Any Ideals ? THANKS >>>>>>>>>>>>>>>>>>>>>

[MT-2500]

Originally Posted by automps

Hello, My 1999 Chevy express is doing the same thing ! I replace the sending unit STILL Does the same thing . Test the gauge with snap on scanner , command the gauge to fill ,goes up and back down . Iam thinking the gauge is screwed up . All wiring sames to be ok . Any Ideals ? THANKS >>>>>>>>>>>>>>>>>>>>>

When comanded up it should stay up untill you comand it back down .
does it do that?

Also Make sure tank unit is getting good ground.

Also check the wiring plugin at the transmission cross member.
I have had a lot of problems with plugin wiring and on some have had to rewire around the plugin.

[automps]

Originally Posted by MT-2500

When comanded up it should stay up untill you comand it back down .
does it do that?

Also Make sure tank unit is getting good ground.

Also check the wiring plugin at the transmission cross member.
I have had a lot of problems with plugin wiring and on some have had to rewire around the plugin.

Thanks for the input, When commanded to full it goes up to half tank . I thing the stepper motor in the cluster is bad . I have checked all wiring ?

[MT-2500]

Originally Posted by automps

Thanks for the input, When commanded to full it goes up to half tank . I thing the stepper motor in the cluster is bad . I have checked all wiring ?

Grounding out fuel sending unit wire should put gauge to full if gauge is working good.
Let us know how it goes.
Good Luck

[mike1016]

I got almost the same problem. The thing is that my gauge is working, when I turn the key to ignition the gauge goes to full tank and then goes back to the real level of the fuel in the tank.Well when is raining or moisture outside the gauge wont to get back to the real level of the tank and stays all the time on full tank and my van does not want to start. Any body knows what can be the issue? 2000 Chevy express 2500.
Thanks in advance.

[MT-2500]

Originally Posted by mike1016

I got almost the same problem. The thing is that my gauge is working, when I turn the key to ignition the gauge goes to full tank and then goes back to the real level of the fuel in the tank.Well when is raining or moisture outside the gauge wont to get back to the real level of the tank and stays all the time on full tank and my van does not want to start. Any body knows what can be the issue? 2000 Chevy express 2500.
Thanks in advance.

Check the fuel gauge ground wire and wiring.
Clean grond wire to frame.
Let us know how that goes.
Also on express vans the fuel pump and sending unit wiring on transmission crossmember has a plugin that gives a lot of problems.

[stylesdude]

I was having the same issue, I replaced my fuel pump, it came with a pigtail to wire in a new plug this worked to fix my gauge. at further inspection of the old pump, the contacts on the float were worn to the point that they only made contact part of the time. so it only showed the real reading when it made contact. also replaced fuel filter at the same time as it was recommended by my mechanic. this may be the fix to your problem. mine has 157000 miles on it.

[Range Rat]

The vehicle we have inherited has a fuel gauge that sits just below the 1/2 full mark when the vehicle is not running. When started the gauge dances to "empty", then "full" then resides permanently just above the 1/2 mark. Same answers as above?

[Poolman45013]

Gas gauge goes to 3 o'clock and van dies. Disconnect battery and van will start if gauge isn't at 3 o'clock.Very sporadic, sometimes runs for 2-3 days before it happens again. New fuel pump,camshaft,crankshaft, throttle position sensors. Help please.