2007 Suburban 2500 LS runs out of fuel early.

[JoeII]

My Suburban runs out of gas with 4-5 gallons still in tank. This happens while towing. When I get it to a gas station, I can only put 34 or so gallons in it. It has the 39 gallon tank/s. I have a drawing showing two tanks, pumps, and an evap canister.

It seems like the smaller tank may not be getting to the fuel system.

Any ideas?

Thanks,

Joe

[txab]

The smaller tank is doing something. It holds around 10 gallons. Maybe you have vent problem preventing from filling completely.

 

The smaller tank has a transfer pump to move the fuel to the main tank as needed

[SouthCo]

Fill up when you get to 1/4 tank or sooner.? Not a great idea to run that low on gas anyway.

[JoeII]

Thanks for the quick replies, but I'm looking for more technical advice from a technician to fix a problem. I used to be able to use all 39 gallons. I typically get gas before empty, but when towing, I like to stay on the road as long as possible. I carry extra fuel when I tow.

Is there a way to determine which tank is not utilizing the last 5 gallons?

Here is my post on another forum, with a drawing of the system: http://chevyforum.org/chevy-forums/showthread.php?t=29073

Thanks again,

Joe

[JoeII]

Any GM Techs on the forum?