fuel pump question

[jcmiller]

Hi,

 

I tried to start my '42 for the first time since November.  I'm not getting fuel to the carb.  I disconnected the fuel line where it goes into the carb and do not feel any pressure coming out of the line when I crank the motor.  Does that mean the fuel pump is bad or could it possibly also mean clogged line, hole in line, or empty tank?  I think I have a quarter tank and also added about 1.5 gallons to be sure and inspected the fuel line and don't see any holes or cracks.  It's a mechanical fuel pump with a glass bowl.  Thx!

[greg g]

Disconnect the house on the suction side of the pump.  Blow some low pressure 10 psi or so, back toward the tank.  There is a filter on the pickup in the tank, the air will clear the filter and ant sediment that might be around it, remove the gas cap when you do this.  You should be able to hear a strong stream of bubbles coming from the filler.  Then reattach the line, disconnect the line from the pump to the carburetor.  Direct the line into a bottle, a 20 ounce soda bottle will work. Pull the coil wire from the coil and crank the starter.  It may take a while to get flow after blowing it out, but you should see fuel flow if the pump is working.  When you get flow, have an assistant crank the starter while you observe pulses into the bottle.  12 strokes should give you six to eight ounces in the bottle.  This is sufficient flow for normal operations.  If you get less than that, you either still have a problem with the lines to the pump, or the pump it self. Some pumps have an internal brass screen filter that may also need cleaning.

[Worden18]

Here’s  what I would do before I would start swapping out fuel pumps or anything like that: 

 

 Hook your line back up to the carburetor and dump some gas down the carb to get the engine started for a bit. That will cycle your  fuel pump a lot faster.   Do that a few times if it doesn’t stay running.  Otherwise if there’s no fuel in the line it takes a long time for 6 V to crank up the fuel from the tank to the carb.  Not saying this is your problem, but it’s a start without tearing off the fuel pump .

Edited August 13, 2018 by Worden18

[jcmiller]

Thanks guys.  In the past I have started the car after long periods of inactivity and agree it takes a while for fuel to get to the engine, but I think I am beyond that amount of time spent cranking the motor (more than 90 seconds, but not all at once).  But, assuming that is the issue, wouldn't I feel some air pushing out of the line at the carb inlet if the pump was working and a column of fuel was on its way?

[jcmiller]

I followed Worden's advice and it worked!  Note to self: it takes at least two minutes of cranking to get fuel to the carb after sitting for a long period.  Thx guys.

[desoto1939]

I would suggest that you put on an electric fuel pump near the gas tank. Then have a toggle switch under the dash. Use this as a primer pump for the carb after the car has been sitting. I have had one on my 39 desoto for 10+ years and they work great.. Also remember that you are positive ground so the electric FP will have its positive wire going to the ground to the car and the negative wire on the Electric Fp will supply the power to the pump.  Put the pump as far back as you can on the frame near the gas tnak. The electric Fp like to push fuel and NOT PULL FUEL.

 

I have also been using hte new stabil 360 product in my gas tank since it is all metal. When the 360 stbil fixes with the gas it creates a vapor that coats the upper top and side of the tank to stop  rust and mositure build up that then drops rust and particles down in the bottom of the tank and then get logged at the outlet line.

 

Rich Hartung

Desoto1939@aol.com