Fuel Pressure Nightmare!

[texas_rat_trap]

I have a '53 Ford Maineline with a '61 Galaxie 223 engine, Cleaned Fuel tank, fairly new Airtex electric fuel pump, new BG Demon 98 2bbl carb. Problem is u can start it at 6-7psi drive the car for around 15min then park back in the drive way check the pressure again and it will now be around 3psi and it will slowly keep coming down till it runs the carb dry cuz the pressure is now 0psi but u can still hear the pump running. I do have a Puralator clear plastic fuel filter before the pump and before the carb. I dropped the tank again today to peek inside because when I blew into the tank it seemed restricted but it was clean. Im thinking the opening in the tank is to small and cant maintain proper fuel pressure. the stock tank was for a 215 single 1 bbl carb. Im thinking I should put a Fuel Cell & Holley electric fuel pump. The carb can handle 8psi & the pump on it now is rated 5-9psi. I've exchanged the pump out once already with the same results. Seems to do better in cooler temperatures. :help: :help: :help: :help: :help:

-Dustin-

 

[texas_rat_trap]

I think Im gonna try a performance electric pump like I had on my '79 Camaro first then if that doesn't take are of it I'll try a fuel cell. I have a gut feeling its the tank though but, will try a pump 1st cuz its easier to get to.

 

[flatford6]

Gas cap that does not vent and let air into the tank as the fuel is pumped out.

A filter that plugs up if water is present in the gas pumped through it.

Crud floating around in the tank blocking off the fuel inlet.

A bad fuel pump, probably something holding one of the pump valves open.

A bad fuel hose which is obstructed inside because of a reaction with new additives in fuel.

The pickup in the tank has a hole in it above the fuel level and so the pump is sucking air.

These are all problems I have had in the past. Good Luck Richard

 

[texas_rat_trap]

Gas cap that does not vent and let air into the tank as the fuel is pumped out.

A filter that plugs up if water is present in the gas pumped through it.

Crud floating around in the tank blocking off the fuel inlet.

A bad fuel pump, probably something holding one of the pump valves open.

A bad fuel hose which is obstructed inside because of a reaction with new additives in fuel.

The pickup in the tank has a hole in it above the fuel level and so the pump is sucking air.

These are all problems I have had in the past. Good Luck Richard

I dont think its any of these problems. I have completly cleaned the tank 3 times and all the passages including the vent tube. I've have inspected the pick up tube and it looks good besides the opening looks small. I've ran it with the gas cap off cause I thought maybe it wasn't venting properly. I've swapped fuel pumps. I think the fuel pump cant pull enough volume through the tank. After running it for a while and the pressure drops to 0psi I pull the hose off the carb & there is air pressure on the hose with no fuel in it & let it sit for a while and it will start back up with 6-7psi then slowly cycle back down to 0psi. I think I'm gonna try a Holley Black Pro Series electric fuel pump with regulator....Free-flow pressure 140gph... Flows 120 gph maintaining 9psi line pressure.

 

[bubba22349]

Are you runing at least a 3/8 inch fuel line?

 

[Lazy JW]

.... when I blew into the tank it seemed restricted ....

It is restricted; you have eliminated everything else.
Joe

 

[StrangeRanger]

I pull the hose off the carb & there is air pressure on the hose with no fuel in it & let it sit for a while and it will start back up with 6-7psi then slowly cycle back down to 0psi.

If there is pressurized air in the fuel line, the pump is working but it is sucking air instead of fuel. That requires a leak upstream of the pump. Take another look at that pickup tube/suction hose

 

[Lazy JW]

......

If there is pressurized air in the fuel line, the pump is working but it is sucking air instead of fuel. That requires a leak upstream of the pump. Take another look at that pickup tube/suction hose

Good point, StrangeRanger; I remember reading a Gus Wilson story about that many years ago but have never actually ran into a suction leak myself. A new fuel line would be in order.
Joe

 

[texas_rat_trap]

Thanks for the input guys...thats pretty much what I thought. The problem must be in the tank because there is only about 8" of line out of the tank before the pump & the rest of the line is new all the way up to the carb. I think I'll replace the tank with a 20gal fuel cell.

-Dustin-

 

[StrangeRanger]

I don't think it's the tank, I think the problem is in the pickup tube

 

[woodbutcher]

Hi SR.After reading this thread,I do believe you`re correct.
One way that I have seen problems like a bad pickup tube fixed,providing it is fixable,is to remove the offending piece of the tube with a tubing cutter and then get a piece of steel tubing that will slide OVER the old tubing and silver solder it in place.then trim it to the proper length.Be sure to properly clean the old and new tubing before soldering.
Just be sure to back off about 50 feet from your gas tank,lest you experievce a VERY loud nasty noise.
Leo