Topic: Electric Fuel Pump


MDB    -- 05-02-2011 @ 7:25 AM
  In order to circumvent traditional vapor lock problem on my 39, I would like to add an electric fuel pump in line while retaining original (either functional or non-functional) for appearance of originality? Which brand/model and location is advisable? We're not aiming for Concourse but attempting to get close as possible. Thanks for any suggestions. MDB


supereal    -- 05-02-2011 @ 10:19 AM
  We use the Airtex pump sold by C&G (800/266-0470) as item 11A-9350-E6. Use the worm screw clamps in place of the spring clamps sold with the pump. Locate it as near the fuel tank as possible, and put an inline fuel filter between the pump and the tank. Connect the power to the pump thru the accessory side of the ignition switch so it is turned off when the engine is not running. We use a spring loaded toggle switch for control. "Vapor lock" is not a "traditional" Ford problem. It is a good idea to find why your car is doing that before you add the booster pump. We install the pumps to help refill the carb after long periods of nonuse, but not to replace the mechanical pump. The "new" gas destroys non-nitrile parts of mechanical pumps and carbs, which will imitate vapor lock. Other causes include a weak ignition coil, and a fuel line partially clogged with rust and dirt. Other places are a non-vented gas tank cap, and dirt/rust in the tank. I chased the problem in my '47. It would balk and buck, then smooth out when the electric pump pushed the gas. Finally, even that didn't work, so I checked the fuel line from the pump to the firewall, and found it almost closed. Twenty bucks and an hour under the car did the job. An unreliable car takes all the fun out of the hobby, as I'm sure you know.


Billc    -- 05-15-2011 @ 9:34 AM
  Could I install the Airtex pump and leave the old pump in place and run the electric all of the time? I have tried several pumps and no gas. This on my '36 pickup with a new line and cleaned and coated tank.

Bill

36 pickup 47 COE


supereal    -- 05-15-2011 @ 10:12 AM
  Yes, you can leave the elctric in place, as the valves in the mechanical pump allow the gas to be pushed thru without a problem. I'm curious as to why, after trying several mechanical pumps, you still have no fuel. I would pull the mechanical pump and stand and observe the action of the push rod. If you have an aluminum intake, the rod should measure 7.87". If you have an iron manifold, it should be 8.87". The chances are, if you have an iron manifold, you may have the aluminum type rod. I've seen it more than once. The only other explanation I can think of is that the cam is flat. The Ford camshaft is very durable, and I haven't seen a genuine camshaft go flat. Be sure that your fuel line isn't obstructed by rust and dirt. We are seeing a lot of that now that alcohol is present in nearly all fuels. The higher oxygen content, coupled with the tendency to dissolve deposits, is creating problems that even an electric pump won't solve.


Billc    -- 05-15-2011 @ 1:21 PM
  I will check the rod, I have an iron manifold so that could be it. The fuel line is new and the tank has been cleaned. I have no E fuel that I use here on the farm and that is what is in the PU. Thanks for the tip.

Bill

36 pickup 47 COE


supereal    -- 05-16-2011 @ 6:35 PM
  Let us know what you find out. As to alcohol in fuel, most, if not all, contains it. It is likely that it was added when the transport hauled different grades of gas, or if an unscrupulous dealer put it his tanks to make extra profit. It doesn't take much to cause problems in non resistant systems.

This message was edited by supereal on 5-16-11 @ 6:36 PM


Billc    -- 05-19-2011 @ 9:02 PM
  Well I checked the rod and it's the proper 8 7/8 inches.
Now it's either an electric pump or drag it around and see if will move gas up.

Bill

36 pickup 47 COE


TomO    -- 05-20-2011 @ 8:37 AM
  Bill, I am confused with your posts.

First you say that you want an electric fuel pump to eliminate "vapor lock" and then in your last post, you indicate that you are not able to run the 39.

Vapor lock is sometimes blamed for other problems such as a weak spark. Check your spark at idle. It should be at least 1/2 inch long, blue in color and make a cracking sound when a plug wire is held close to a head nut, using a plastic handle screw driver or a fuse puller to hold the wire.

Vapor lock is caused by a weak fuel pump or a plugged or leaking gas line.

To check fuel delivery, you need a graduated 16 ounce or larger container to determine the amount of fuel delivered in a measured time. Disconnect the fuel pump line from the carburetor and direct it into a graduated container. Crank the engine long enough to get 2 ounces of gas in the container and then continue cranking for 15 more strokes of the pump. The pump should have delivered 6 more ounces of gas.

Check the sediment bowl in your fuel pump for rust. If there is rust in the bowl, your gas line may be partially plugged. If there is no rust, you could still have a problem with the flex line leaking or plugged up.

Tom


supereal    -- 05-20-2011 @ 9:50 AM
  Did you check to see that the pump push rod actually went up and down as the engine turned? If it doesn't, there is a strong possibility that someone installed the rear camshaft bearing improperly. The bearing has a hole in it that allows the rod to reach the cam. If the bearing was installed with the hole not facing up, or was turned enough to prevent access, the pump can't be actuated.


Billc    -- 05-21-2011 @ 5:08 AM
  TomO,
I posted my fuel pump question on MDB's thread and I should have started my own, sorry. I am trying to start an old truck that hasn't run for a long time and anything in the sediment bowl would be progress. My problem is no gas.
supereal,
Yes, it does move. The truck runs with a little gas in the carb but it takes too long maybe to get fuel all the way up to the engine on the battery and it drains back to the tank? Once the fuel gets to the pump is there a check valve to keep the line full?
Bill


36 pickup 47 COE


supereal    -- 05-21-2011 @ 7:22 AM
  There is a set of valves in the fuel pump that act as check valves. If the pump is in good condition, but can't deliver, it is possible the the fuel line is plugged, or has a hole it it between the tank and the firewall. More likely is that the tank is partially filled with crud and water. This may have caused the pickup tube to rot away. Hook up an alternate source of fuel to the pump and see if the truck will run. It is a good idea to see what is in the tank before installing an electric pump, anyway. Be sure the tank actually holds gas, not water, diesel, or other material that can't be pumped. We see a lot of that in long stored vehicles.


TomO    -- 05-22-2011 @ 5:42 PM
  Here is a procedure to check out the fuel pump with a vacuum gauge. If you do not have one, I would budget for one as they are a very useful tool for trouble shooting engine problems and adjusting the carburetor.

If you are having a problem with priming the fuel pump, hook a vacuum gauge to the input of the fuel pump and crank the engine. The vacuum gauge reading should rise to 10 inches in 18 seconds. Stop cranking the engine and watch the needle on the gauge. It should take at least one minute to reach 0. In order of probability causes of failure in this area are top cover or sediment bowl gasket leaks, input valve not working or defective diaphragm. The valves in the new after market pumps made by Air-Tek will not hold vacuum above 5 inches. This may lead to priming failures. The valves in the pre 1941 fuel pumps are more likely to fail than the later type.




Tom


Billc    -- 05-23-2011 @ 1:24 PM
  It runs! My brother disconnected the fuel line from the pump and could hear a gurgle of fuel going back into the tank I guess. That led us to think that the pump was working just not enough at one go with the battery. We put a chain on it and pulled it and soon had gas in the bowl. After moving the ignition wire to the right place it started right up! Thanks to all for your help.

Bill

36 pickup 47 COE


TomO    -- 05-23-2011 @ 6:09 PM
  Bill., if you had to pull it in order to get gas to the carburetor, you still have a problem. Either your fuel pump valves are not working or you have a vacuum leak in the lines before the fuel pump.

Tom


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