LRA Issues and Insight Needed

[K9LTW]

Welp. She’s pumping fuel really well into the main tank filler neck. Not the best picture but it was a strong pulse. I can see it being somewhat problematic, though, with splashing back into the auxiliary fill neck; particularly with going uphill as it was splashing out a bit even sitting flat.

I’ll drive it down to showing a quarter tank (which is barely less than a half tank in reality) and then perform a test sitting there idling.

Given the pump appears to be working correctly, it may be a sensor/float issue. Or it’s just super sensitive to hills and something I just need to be cognizant of.

 

[K9LTW]

Used the Land Bruiser to commute and have a relatively flat distance to test things out, again. Happy to report...it seems to be working as intended. I'm guessing it really doesn't appreciate constant ups and downs all that much. Not surprising given how much splatter there seems to be. I feel like it would've benefitted from the aux output into the main filler tube being lower. Or even some kind of hinged flap like on most OEM fill ports.

Either way...the gauges worked as expected, no mystery refilling of the aux tank, etc. I did run the LRA twice until I got the beeping and auto-shutdown. When I refueled, I put 9.25 gal in it (12.5 gal unit). Given all the reviews that they're all but impossible to truly empty, I felt that was within "normal". I know I could pull the drain bolt in an absolute emergency.

Thanks all for the troubleshooting ideas, manuals, and general support. Good lesson learned, IMO, how this thing works.

 

[TeCKis300]

Used the Land Bruiser to commute and have a relatively flat distance to test things out, again. Happy to report...it seems to be working as intended. I'm guessing it really doesn't appreciate constant ups and downs all that much. Not surprising given how much splatter there seems to be. I feel like it would've benefitted from the aux output into the main filler tube being lower. Or even some kind of hinged flap like on most OEM fill ports.

Either way...the gauges worked as expected, no mystery refilling of the aux tank, etc. I did run the LRA twice until I got the beeping and auto-shutdown. When I refueled, I put 9.25 gal in it (12.5 gal unit). Given all the reviews that they're all but impossible to truly empty, I felt that was within "normal". I know I could pull the drain bolt in an absolute emergency.

Thanks all for the troubleshooting ideas, manuals, and general support. Good lesson learned, IMO, how this thing works.

Good to hear. Give it a few cycles and you'll get into the rhythm of using it.

 

[kcjaz]

Even with two full tanks, you can see the transfer into the main tank inlet. It's impossible to overfill the main tank because the fuel just spills back over into the aux tank inlet.

This is true but that recirc back to the aux tank is at the gas cap which means if your doing that you have fuel level in the main tank that high which is above the evaporator & CC which isn’t good. It’s like topping off your gas when you fill until it runs out the gas cap. Never top off, and avoid recircing gas back to the aux tank.

 

[kcjaz]

EDIT: What's the silver thing before your fuel pump? I don't know if I have one of those (but can't remember for sure).

Looks like a fuel filter. Maybe it’s clogged with something. Odd if its new and just installed but maybe there was something in the fuel line related to the install???

OP, I have an upgraded pump too (though different from yours). I get 1 gpm. I measured this by filing the aux tank, transferring for 10 minutes, then refilling the aux tank then doing the math. The gas gauges lag a lot. Especially the OEM main tank. When I transfer, I run the pump for 12 minutes with the main tank at 1/4 left. The main gauge doesn’t move until 10 to 12 minutes then jumps the 3/4. Sometimes it doesn’t move until after I stop the pump.

 

[hoser]

This is true but that recirc back to the aux tank is at the gas cap which means if your doing that you have fuel level in the main tank that high which is above the evaporator & CC which isn’t good. It’s like topping off your gas when you fill until it runs out the gas cap. Never top off, and avoid recircing gas back to the aux tank.

Maybe in theory but not in practice. The transfer pump dribbles fuel into the main tank vs a gas station fuel pump which flows at least 10x that rate. Almost everyone who has the 24-40 gallon tank has certainly "overfilled" the main tank on the transfer. I usually transfer when the main tank is at 50% and again when it hits 50% for weight balance. I have had a 24 Gallon aux tank in one of my cruisers for twenty years now and on the original charcoal canister.

 

[kcjaz]

Maybe in theory but not in practice. The transfer pump dribbles fuel into the main tank vs a gas station fuel pump which flows at least 10x that rate. Almost everyone who has the 24-40 gallon tank has certainly "overfilled" the main tank on the transfer. I usually transfer when the main tank is at 50% and again when it hits 50% for weight balance. I have had a 24 Gallon aux tank in one of my cruisers for twenty years now and on the original charcoal canister.

I agree that a fuel station gas pump is a lot more pump than what’s going on when you transfer fuel. I also agree that most LRA owners overfill the main tank at least a couple times especially for the 24 gallon and 40 gallon sizes as it’s very easy to do. That said you do not want liquid fuel in your charcoal canister as it is designed for vapor so I guess the question is does having a liquid fuel level at the gas cap allow fuel into the charcoal canister. I think the answer to that question is yes, but is it in enough to cause any real issue? I don’t know the answer to that for sure. All I’m saying is you don’t want that to happen if you can avoid it. The 200s with LRA’s sure seem to throw a lot of Evap system codes compared to 200s without LRAs. Many here have had to replace their charcoal canister to resolve issues. I’m about to replace mine is clearing the codes is getting old. I haven’t been able to find what’s causing the problem yet so hopefully I will find my canisters OK and it’s just a system leak somewhere.

It may be just a coincidence, but the frequency of throwing codes increased shortly after overfilling my main tank at a gas pump that didn’t shut off, and I had walked to another part of the truck and didn’t notice till I saw gas all over the ground.

 

[mbennett22]

I have had this question for quite a while. I have the 40 gal aux and often forget to turn it off cause of how slow the pump is, maybe if it was faster I would remember. That being said I have often wondered if "overfilling" is an issue or does the fuel go back to the aux tank. Wish these would auto shut off when the main tank was full.

 

[mobi-arc]

I added a timer relay and set it for 10 minutes.