Any issue with using a gravity feed auxiliary fuel tank on an LBZ?

[Dozerboy]

I added a tank to my LBZ to get more range while towing. My understanding is my stock tank won't overflow or anything if I open the valve right away with both tanks full.

What about any CELs from the fuel gauge reading full for a long time? I thought I recall that being a problem. Can that be corrected with EFILive?

 

[clrussell]

The only problem I have with my 60 gallon in bed tank is the fuel gauge will eventually bottom out and the fuel light will come on (about 100 miles from fill up). It’ll reset every time your start and when you get to using the truck tank it’ll start working again.

 

[2004LB7]

I've used a gravity feed aux tank on my LMM. worked fine. just dont take the filler cap off for the regular tank while it's under pressure.

had the fuel gauge problem like everyone else. not sure how you can correct it with efi live. the gauge drops to empty until it sees some movement on the sensor. no settings for this in efi live. not a big deal as it resets automatically when it starts drawing down the stock tank

 

[jlawles2]

I ran an 18 gallon gravity feed siphon tank into the main tank on my 06 LBZ. I would fill the aux tank, then the main tank and then top off the aux tank while it was feeding the main tank by siphon. Once the main tank fill level got to the vent tube in the neck, I would then put on the main tank cap and finish topping off the aux tank. Before I started the truck, I would pump the bulb (used a boat primer to start the siphon) a couple of times and off. At the 100 miles from fill up the fuel gauge would drop to E, light come on and ding a couple of times. Every multiple of 100 until the truck saw sensor movement it would do the gauge trick. Did not make a difference how many times it was restarted between the 100 mile interval.

 

[LBZ]

It works as long as the aux tank is vented both ways not just to allow air in as many are. If the tank ever pressures up ie. hot sunny day it will over come the fuel cap relief and you will make a mess.

 

[Dozerboy]

Thanks guys. I hate having the CEL or the fuel gauge acting up. So I have just been opening up the fuel valve at 3/4 tank and not had any issues with the fuel gauge.

I burn fuel faster then the tank fills..lol

 

[NevadaLLY]

Thanks guys. I hate having the CEL or the fuel gauge acting up. So I have just been opening up the fuel valve at 3/4 tank and not had any issues with the fuel gauge.

I burn fuel faster then the tank fills..lol

I use a gravity feed tank in my truck. The best trick is to add a manual switch and fuel solenoid valve on the feed line. You'll want a naturally closed solenoid. I did this and can flip the switch on/off whenever I feel like it. As you had thought, the truck can't run on "full" for too long or it sets an error code assuming the gauge isn't working. I usually switch the feed on around the 3/4 mark or lower and haven't had any problems. It's nice to see the gauge actually go up while towing .

 

[LBZ]

I use a gravity feed tank in my truck. The best trick is to add a manual switch and fuel solenoid valve on the feed line. You'll want a naturally closed solenoid. I did this and can flip the switch on/off whenever I feel like it. As you had thought, the truck can't run on "full" for too long or it sets an error code assuming the gauge isn't working. I usually switch the feed on around the 3/4 mark or lower and haven't had any problems. It's nice to see the gauge actually go up while towing .

I put a solenoid valve on my ‘16. I still had a transfer pump but it was nice to be able to shut the tank right in as the pump would leak past and after a couple days of being parked it would fill the truck and then I’d get a leak if it got hot.