Engine: 56 Hawk stalls going uphill at low speed

[terryb]

My 56 Hawk generally runs pretty well. I added an electric fuel pump and believe I am getting reliable fuel to the Stromberg carb. It climbs hills fine at normal road speed but stalls out climbing the steep hill on my driveway at low speed. I can barely make it up if I give it hardly any throttle. Any additional throttle causes a stall. I'm stumped at this point.

[Buzzard]

You could have lost the fuel sock on the suction pipe in the tank. Low speed wouldn't allow there to be enough fuel in the line to supply the carb.
Luck, Bill

[PackardV8]

Have you verified the float level is set correctly?

jack vines

[Bud]

If I remember correctly, Studebaker did not use a sock or filter on the inlet pipe in the tank as the original fuel pumps used a ceramic filter element in the fuel pump, so that is not your problem. A vacuum leak could be your problem though causing the fuel mixture to go lean at low throttle settings. Your Stromberg carburetor is now 65+ years old and I'm sure that it has a good amount of wear on the throttle shaft and bores that will cause a vacuum leak along with other warped or worn out parts in the carburetor. Bud

[JoeHall]

Sounds like a fuel delivery problem, so maybe the pump is marginal in fuel delivery. What is its flow rating, in PSI and quarts per minute. Also, where is it located? Some pumps are capable of suction, and some are not, so it may be when you start uphill, gravity overcomes the pump's ability. Are you, by any chance running a return line? If so, maybe block it off temporarily and see if that helps. Many electric pumps do not have enough volume to support a return line.

[altair]

Try going up in reverse and see if any change, that will tell you it is the carb.

[JoeHall]

Try going up in reverse and see if any change, that will tell you it is the carb.

Or in fuel delivery, i.e. the fuel pump.

[altair]

Or in fuel delivery, i.e. the fuel pump.

I think the fuel pump would be the lesser of the issues, I have tested fuel pumps standing 10 feet on a ladder with a hose attached to the inlet into a container of solvent and the pump delivered the fuel within about 6 strokes and squirted it at least 6 feet. A fuel pump will work upside down, on its side or any angle, if the car was standing on its trunk it would still pump fuel, however a pin hole in the delivery line could change all of that. With a carburetor bowel full of fuel, the engine should run for about 2-3 minutes, in gear it should travel at least 200 - 300 feet, therefore IF the bowel was full it should have no trouble negotiating a short 10% driveway.

[JoeHall]

I think the fuel pump would be the lesser of the issues, I have tested fuel pumps standing 10 feet on a ladder with a hose attached to the inlet into a container of solvent and the pump delivered the fuel within about 6 strokes and squirted it at least 6 feet. A fuel pump will work upside down, on its side or any angle, if the car was standing on its trunk it would still pump fuel, however a pin hole in the delivery line could change all of that. With a carburetor bowel full of fuel, the engine should run for about 2-3 minutes, in gear it should travel at least 200 - 300 feet, therefore IF the bowel was full it should have no trouble negotiating a short 10% driveway.

The OP said he 'added n electric pump'. Not sure where he added it, or what kinda pump it was. Electric pumps vary: some can siphon, some cannot; some allow fuel to be drawn through them, some do not, and some are just plain junk, right outa the box. I was focused on the electric pump, not even sure he has a mechanical pump. But must admit I never stood on a 10 foot ladder and tested either electric or manual pump.

[terryb]

I have also noticed that it does struggle to accelerate from a dead stop even on level pavement. I can feel the vibration on the accelerator pedal. Runs fine when it reaches 20 mph. Makes me wonder if it is a transmission adjustment issue. I know there is a linkage adjustment between the transmission and throttle position. Thoughts?

[JoeHall]

I have also noticed that it does struggle to accelerate from a dead stop even on level pavement. I can feel the vibration on the accelerator pedal. Runs fine when it reaches 20 mph. Makes me wonder if it is a transmission adjustment issue. I know there is a linkage adjustment between the transmission and throttle position. Thoughts?

Need more info: Is your 56 Hawk a six cylinder or V8? What is the fuel pump arrangement? Both electric and mechanical? Only electric? Only mechanical? What make and model are the fuel pump(s)? Have you inspected the fuel tank? Fuel lines? Fuel filter(s)? Why did you install the electric pump in the first place? Any other pertinent info?

[Bud]

If the engine has a Stromberg WW carb on it then, the car in question has to be a Power Hawk as they were the only ones in 56 that used a 259 and a Stromberg two barrel carburetor. The Flight Hawk with the 185 would have a Carter WE carburetor and the Sky Hawk and Golden Hawk used Carter WCFB four barrel carbs. Bud

[StudeRich]

Have you given any thought to checking the Fuel Pickup Line that WAS (when New) IN the Fuel Gauge Sending Unit unless you have a Newer Model Hawk Tank?

If that tube has a problem like being bent, rusted out etc. you will have fuel shortage especially when Your Power Hawk is below 3/4 or 1/2 of it's 18 gal. Max Tank Capacity.

It is accessible through the Cover in the Hole in the trunk Floor.
You will need 5 small Copper Crush Washers and a New Sending Unit Gasket before inspecting the Sender, Pickup Tube and the inside of the Tank.

The reason I suggest that is; the Pickup line is nearer the Front of the Tank so Up hill is not good if it does not reach near the bottom or is not solid.

https://studebakervendors.com

[Jeffry Cassel]

Float level. In college, thought I would put a kit in the Rochester 4GC in my Buick. Went to the drive in theatre that evening and after a double feature, the car wouldn't start. As you might remember, you parked on a little rise so you could see the screen more easily. I immediately guessed what I had done wrong and we pushed the car down our little hill and part way up the one behind us. After a minute or 2, it started right up. Drove home without incident and the next am re-adjusted the float level. Problem solved. It is a 2 part problem and it has more to do with the angle of the car and fuel delivery than anything else. If it were anywhere else in the system, the more demand , the worse the fuel starvation would get. A WCFB isn't all that different from a 4GC. Sensitive to float level.

[terryb]

This car is indeed a 56 Power Hawk with a 259 V8 engine. I have removed the carburetor and the float hinges from the right side, so I would think that it would be unaffected by the orientation of the car going up hill. Also the the float position as I measured it seems to be dead flat when floating. I have been led to believe this is the proper set up. The tank level is at about 1/4 full so there could be an issue with the fuel intake pipe from the tank. I would have thought that there would still be plenty of fuel in the carb and the fuel line to allow me to get up my driveway even if it stopped getting fuel from the tank for 15 seconds.