Fuel pump rod lift

A

arc40s

Member
I have a 59AB 1946 engine
I have tried four different fuel pumps(with glass bowl and pump with out), flex hose and fuel pump rods with no luck. I have added 3/16" thick leather shim between pump lever and pump rod. Engine will run on electric pump but not on manual pump. no leaks on any connections.


Question is what is correct fuel pump cam lift? 1/4" , 7/16" or 1/2" more?
Does this lobe have a tendency to wear?
How do I repair or replace other than swap out camshaft?
Again what is correct lift on fuel pump cam lobe?
 
Re: Fuel pump rod lift0

Most are appox. .200 travel. If you have the travel then either the pushrod is too short or there are problems with the pump.
 
Try cranking the engine with the fuel pump off and be sure the pushrod is moving up and down approximately .2". If the rear cam bearing is a little too far back, the push rod may not be getting down to rest on the cam.
 
I don't know how your pick up in the tanks is made but on my 50 the tube is welded to the bottom of the tank in a recess to pick up as much of the fuel as possible, mine had a half moon cut at the end of the tube and then bent down to cover the opening. The problem was anything small in the tank could cover the opening and stop the pump from working. I can reach in my tank through the sending unit hole from inside the trunk, I took a long blade screw driver and opened up the end of the line. I now run a clear fuel filter before the pump so I can see anything that may be in the fuel. I've been told by some long time flat head guys that the stock pumps didn't supply a lot of fuel in some cases, most people run a electric pump on modified engines.
 
Try working the pump arm by hand,hook up the supply line and give it a try, be careful not to over extend the travel. You should be able to pump fuel out. I've done this before to fill the bowl before installing the pump.
 
Any pin hole that deletes the vacuum will stop the pump from sucking fuel from the tank up to the carb. First place I always check is the gasket at the pump cover and also the bolt that holds it down. I also always check to make sure the valves are opening and closing. You can test the pump with a vacuum gauge off the car to see if it is creating a vacuum. Once you are SURE there is no problem with a pump, you can go to the next level and as suggested eyeball the end of the rod and see that it indeed is going up and down. If all that checks out, run a line from the pump to a small gas can and see if it will pull gas from there. Old hard lines get clogged and/or pinholes that will stop the pump from working. I keep known newly rebuilt pumps to take along in my cars and wouldn't trust just swapping on and off other pumps. You should be able to figure this out. Maybe there is just so much crud in the tank it clogs the supply line to the pump.
 
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