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Gump159 · 03-18-2019, 01:46 PM

The motorhome is a Southwind 1988 P 30 chassis w/454. It sat idle and un-run for approximately five years. I have installed a new Electric booster fuel pump but I am not able to draft out of the gas tank. The tank was drained of old fuel and approximately 30 gallons fresh Fuel was added. The rubber fuel line feels like it is collapsing on demand of the pump. I used air pressure on the line of approximately 30 PSI but it did not bleed back into the tank. Does anyone know if there is a backflow check valve located between the draft line and the booster pump ? In or out of the tank? I am open to any helpful information on how to get the fuel flowing. The rest of the fuel system seems to be OK I used the booster pump and sucked fuel out of a gas can in order to fill the tank. Thank you in advance for your time and consideration

exrench · 03-18-2019, 02:48 PM

If the pump suction is causing the fuel line to collapse,and 30 psig will not pass air, then whatever is causing the blockage will be accessible only by dropping the fuel tank. One can only speculate what is causing the blockage. You will notice the pick-up does not reach down to the bottom of the tank to ensure the generator does not deplete the entire gasoline supply. When you solve the supply problem,the ogre of gum in the carburettor, resulting from the 5 year hiatus, may have to be faced with $$. Good luck.

Tha_Rooster · 03-18-2019, 02:55 PM

I believe they have a fuel filter tucked inside the frame rail maybe stopped up.

Outbound · 03-18-2019, 04:37 PM

I agree with plugged fuel filter, 30 psi of air would move anything in tank out of the way, if you have crud in fuel tank you will need to carry extra fuel filters, replaceable core type would expedite changes.

ScoobyDoo · 03-18-2019, 04:53 PM

Not sure, is there a pump inside the tank? A pump not running will rarely let anything flow. If there is a chance, drop the tank, and before you replace the pump clean the tank. A clean tank will reduce problems after you get it running...

exrench · 03-19-2019, 06:16 PM

Back in the 80's a fuzzy fuel filter was often found on the fuel pick-up hose.I would speculate this could become a gummy mass in a gasoline tank that had a 5 year holiday. Let us know what you find.

keymastr · 03-19-2019, 06:39 PM

1988 most likely did not have fuel lines that were compatible with ethanol fuel. All the rubber components will likely need replacing. After sitting that long the entire fuel system will need going through.

I am guessing your theory of the fuel line collapsing is correct. Nothing short of replacing it will work for long.

Bob_C · 03-19-2019, 06:47 PM

Fuel pump is in tank......pull it out and jumper it.....

ScoobyDoo · 03-20-2019, 05:08 AM

Quote:

Originally Posted by exrench

Back in the 80's a fuzzy fuel filter was often found on the fuel pick-up hose.I would speculate this could become a gummy mass in a gasoline tank that had a 5 year holiday. Let us know what you find.

If the sock filter was the only issue, 30 PSI blowing thru the line into the tank would remove it. (Did this more than once on cars that had cam driven pump)

Quote:

Originally Posted by keymastr

1988 most likely did not have fuel lines that were compatible with ethanol fuel. All the rubber components will likely need replacing. After sitting that long the entire fuel system will need going through.

I am guessing your theory of the fuel line collapsing is correct. Nothing short of replacing it will work for long.

Yes, it is likely all the rubber lines will need replaced (and inspect the steel, rust can weaken, leak) before you have a dependable vehicle. But if it will run when hooked to another supply, I would concentrate on tank area, make it pull fuel from tank. Once I got that working I would replace the rest. Don't open too many doors for Murphy at once.

Quote:

Originally Posted by bob caldwell

Fuel pump is in tank......pull it out and jumper it.....

.pull it out Move away from tank and jumper it.

Rkesselus · 03-20-2019, 10:27 AM

agree with starting with the in the tank pump. If you jump the 12v to the pum[ will it run, you will hear it. If it is stuck or just not working I would agree that there is a check valve of sorts that might prevent back pressure to clear. What happens when you try to get fuel out to the generator will that line flow?

tropical36 · 03-20-2019, 01:42 PM

Quote:

Originally Posted by bob caldwell

Fuel pump is in tank......pull it out and jumper it.....

Are you sure?
The ones I've seen of this era, have an electric pump and filter on the outside of the tank which gets it to the GM mechanical pump on the 454 carburetor engine.
There's usually a split that goes to the genset, back by the tank.
Don't believe anything was said, about the genset, with running or not.
Either way the tank needs dropped or an access hole cut into the floor above, for not only replacing the hose, but for having a look inside the tank at the pickup tube, which could be completely rusted away by now.

theoldwizard · 03-20-2019, 02:56 PM

Using "rubber" fuel line with a pump capable of 30 PSI is asking for a DISASTER !

Waiter21 · 03-20-2019, 03:00 PM

I believe the pumps inside the tank are a turbine pump. These may not allow you to draw through them..

Do you have a generator? Does it have a separate feed that you could "T" off of to test your external pump..

NOTE - I believe the max pressure you want to go with on a carb engine is about 6psi.

Gump159 · 03-20-2019, 03:22 PM

The generator runs independently and cuts off at a little less than a quarter of a tank. This line looks like it is going to complicate dropping the tank because it’s steel and goes through the frame rail The fuel return line is tucked inside the left frame rail and doesn’t feel like there’s enough slack in it to drop the tank. I am beginning to think they gave a fuel tank to Waldo and said “here, go build a motorhome around it.” Thank you everybody for your input