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fuel pump not working. pump is good. it been changed out twice in last few days. tried everything. engine will run if you pour a little gas in the carb. when it's gone the engine will die. thought I had gotten a bad one but the fuel pumps were good. is it possible the camshaft lobe where the fuel pump hit is worn out? if so, any solutions other than changing the camshaft? the fuel pump stopped working after driving a few blocks from the house. yes, there's plenty of gas and the lines are all clean with a new fuel filter. it's a 250 straight 6. luckily I had left the electric fuel pump mounted and just re-hooked it back up. it pumps fine but I would still like to do something about the mechanical pump.

blkhrn,

You must be the 'King of Contradiction'. The rig would not go several blocks with a flat fuel pump lobe. You say both pumps you installed are good, but they won't pump? If they won't pump, how the heck did you drive several blocks?

If the pumps are correct for the engine, and were installed properly and don't work (?) my bet would be on a plugged line from tank to pump.

Your troubleshooting needs to be redone and refined...it doesn't add up to anything. :confused:

Stuart

if it runs alright with the electric pump, not likely to be plugged lines, but it may go a bit if you got the wrong fuel pump with an actuator arm not correct size - what get's worn isn't the cam lobe, it's the actuator arm, and some pumps for different [or multiple] applications may not have the correct actuator for your 250 .... unless 250's happen to have 'soft cam' problems, but I can't see the cam being softer than that cheesy actuator arm

Bill

Insure the the fuel pump is installed properly.Some times the actuator can be on the wrong side of cam.

blkhrn,

You aren't trying to pull fuel through the installed electric fuel with the mechanical pump are you?

Stuart

Put a gauge on the pump. It should put out 3-4 lbs. pressure on the outlet & have several in. of vacuum on the inlet.

Had the same problem on a 1948...tried all the fuel pump stuff....my truck would not go up any kind of hill....there was an old rag floating around in the gas tank that someone had used in place of a gas cap..it drove me nuts until I took the tank out. On my diesel tractor some kind of bug cocoon fell in and did the same thing...now I always filter my gas and diesel...fuel pressure will as give you some kind of indicaion...Steve

stuart
Not a king here! I started having trouble with the original pump after I had driven a block from my home. I started troubleshooting and found no fuel coming out of the pump. That's when I changed out the pump. I checked two new pumps(different ones),after taking them off and they pump fine. The pumps were installed properly. While holding the mechanical pump(bolts not tightened) to the engine block and having someone turn the engine over I can barely feel the cam touch the pump. That's why I'm thinking the arm isn't long enough. I'm not trying to pull fuel thru the mechanical pump with the electric one. I hooked up the electric after troubleshooting. The mechanical pump is blocked off. All the lines were blown out and were clean. Still not pumping. Inline filter is new. It's right below the tank. The fuel is flowing thru the filter and up to the pump when engine is off(gravity). I hung the line below the mechanical pump. There is no blockage in the tank. The fuel comes out fine. After re-attaching the fuel line to the pump, it won't go thru. Do they make the same pump with a longer arm. I exchanged the first pump because I thought they had given me the wrong one. I can't check the outlet pressure because there is no fuel coming out. I hope someone has dealt with this problem before and solved it.

blkhrn,

Great explanation. After reading this, it sure sounds like the wrong pump for your engine. When installing a typical pump on the earlier engines..216/235, it is a chore to compress the pump arm against the cam lobe, even with the lever on the heel.

I might be the 'King of Confusion'. I guess my choices would be wrong pump for the application, suction blocked or pump installed improperly.

What else could it be. It's a puzzler, keep us posted.

Stuart

There you go - you found the problem...

Don't know about the 250, but 235 fuel pumps over the years had different lever angles, matching different cams and engine blocks.
I have found 4 different ones for the late 40s-62 235s so far.
Some pumps have such a wide angle ending up too close to the cam lobe, that they will eventually fail after a few hundred miles of pounding the delicate mechanical parts inside too hard.
The smaller angle lever pumps will pump less or barely any gas and the others can flood your carbs, without an additional regulator.

The bummer is, you just can't go by vendors having the right pump for the right engine block year or whatever replaced cam may be installed.
Most sold are remanufactured and they can end up having different lever angles from different pumps.
It's a matter of luck, experimentation and comparison to end up with the right pump.
Took me 4 tries and two broken new pumps (of course both times being farthest away from my garage...) to finally end up with one that delivers just the right amount of gas - not too much - not too little.


! Careful when buying NOS fuel pumps - Just like with NOS carbs, master and break cylinders - they need rebuilding with fresh rebuilt kits.