Fuel System: The fuel phantom

[keithwahl]

Hi All:
I am the proud new own er of a 1957 Golden Hawk. This is a complete running car which had been restored.
John Erb rebuilt the supercharger and all systems are in great working order
EXCEPT>>>>>>>>>>>
When I go up a hill, i start to starve for fuel unless i turn on my electric fuel pump.
iF I DO NOT TURN ON THE ELECTRIC PUMP THE CAR WILL DIE
THE COMMON LINK TO THIS ISSUE IS UP A HILL - TYPICALLY AT LEAST A 30 DEGREE INCLINE
I have a new mechanical pump by Studebakers west
I have a fuel pressure gauge and I put out about 6-8 psi (factory setting is 6-7)
I have the linkage set up so that when the accelerator is deressed the electric pump is triggered and the fuel pressure is 8-9
The car is properly timed
The car idles at 500 rpm
I have a clear in line fuel filter and the gas is clean
The car will start immediately in the morning and there is no missing when running.
THE FUEL ISSUE IS CONSISTENT WHEN GOING UP A HILL
The fuel inlet is on the bottom of the tank./.. I am told that perhaps the tank was replaced as the original tank inlet is on the top
WHAT THOUGHTS HAVE FUEL SAGES????

[doofus]

This sounds like like a weak mech. fuel pump, not enough suck. test the inlet side of the pump. also where is your fuel filter mounted? right before that electric booster pump? i would have one right before the mech. pump as well to strain out the line debris. Luck Doofus

[Mrs K Corbin]

float issue?

[345 DeSoto]

Float adjusted too low...

[altair]

It sounds like a pin hole or pin holes in the fuel line, the vacuum pump cannot overcome the leak and sucks air, the electric pump is a pressure pump and the pin hole will not affect its operation. Check your fuel line for pin holes disconnect it from the pump and blow very low pressure in to it and spray soapy water on the line, look for bubbles. I had a similar problem the fuel pumps would not deliver fuel (tried three pumps), sprayed the line with soapy water and there were bubbles every where. With a vacuum pump there would be no visible leaks.

[keithwahl]

Brand new mechanical pump
Fuel filter .clear type mounted after pump on way to carburetor

[keithwahl]

Brand new mechanical pump
Fuel filter .clear type mounted after pump on way to carburetor
Float was actually too high and was adjusted
Correctly..NOTE...this only occurs going up a hill..totally consistent
Prior owner relied solely on electric pump
COULD IT BE THE PICK UP TUBE IN THE TANK??

[gordr]

I think Altair has the answer. If the pickup tube in the tank were compromised, it would affect the electric pump, too, and the problem would likely go away with a truly full tank, and get progressively worse as the level in the tank went down.

One other thing. Does it have a vented gas cap?

[leroy]

What size is the fuel line? I may be wrong but l thought the GH is larger being a 3 eighths and did come out the top in the fuel sending unit. IF tank was charged to bottom outlet it's probably 5-16th

[jrlemke]

My 61 Hawk had a 3/8" outlet on the bottom edge of the tank and the tank end of the fuel line was 3/8" for about the last 4" and 5/16" the rest of the way to the fuel pump. I don't remember what the '62 tank I replaced the original with had because I replaced the whole thing at that time. -Jim

[bensherb]

Simple fix; don't climb trees. Where in California are you driving up a 30 degree incline? That's one hellofa steep road. Here in Nor-Cal I know of only one road that steep and they built a bypass around it decades ago.

[keithwahl]

Leroy you are correct The original came out the top and this one comes out the bottom. Gordr, the problem still exists with 1/2 tank going up a hill and it is cured by the electric pump.. I have a fuel pressure gauge and the manual pump is putting out up to 8 on its own. General operating pressure is 6 to 7 which is factory according to the manual. Prior owner used electric pump exclusively. JRlemke--- what is the significance of the outlet diameters?

[keithwahl]

we have a lot of hills.. can't always be on a flat road.
This car should be able to operate without the electric pump and should not die of no fuel up a hill!

[keithwahl]

Gordr I have a locking gas cap and it is loose enough when locked that it should vent

[leroy]

I believe the 6 to 8 lbs would deliver less volume in a small line than the same pressure in the larger line, the GH and later R engines used the larger fuel line I believe.