84 chieftain won't run on Aux tank very long,chev 454

[jwjetco]

I have had this rv for a couple of years and is has gotten to where it won't run on the aux tank. It runs best on level road but up or down hill makes it start acting like it is running out of fuel. MAin tank runs fine in all scenarios.

Any ideas would be apprciated muchly.

[RV Wizard]

Check fuel lines from axillary tank to switch over solenoid. You might also check to be sure the axillary tank is vented properly and it is not developing a vacuum. Good luck and let us know what you find.

[jwjetco]

I ran the vehicle with the gas cap off, this it is vented well.

Took the fuel line loose from the crossover valve and I have gas to the valve and out of the valve.

Could it be water?

If it were the filter would it be consistent or would be intermitant.

Please comment if you can!!!

[Rapid Ray]

You may have a tank of bad gas. Happened to me once, and I cleared it by switching over to the bad tank when going down hills or on lite load. Used the good tank for the major work loads. If you don't have much in the tank that is giving you trouble, I suggest draining that tank or putting new gas into that tank.

[born2camp]

Had an uncle that had an 84 Chieftain with similar problem on his aux tank. After checking everything as you have, vent, crossover hose etc, we ended up dropping the tank, pulling the sender and the "nylon" type sock had a kink right as the fuel goes up towards engine. We figured it was sucking/kicking shut. We also found the rubber hose to the crossover valve was soft and may have been sucking flat because of the resistance in the tank. I cut the sock off the inlet, replaced the fuel line from the tank and put a good in line canister type fuel filter on. He never had the problem again.