Or worn thru. Be sure to use a high pressure zinc additive in your oil.

 

I have but just the last time I changed the oil, so the damage may have already been done!

 

This is the exploded diagram I found in the shop manual. PArt #6287 would be the fuel pump eccentric.

 

That's funny Jag! Thanks for the "jocularity" as Father Mulchahy used to say on MASH.

And no I am going out to remove the new pump and stick my finger in the hole! Or at least use a mirror to see what it looks like.

 

Pin envy, Jag?

 

What's the latest on this, Abe?

 

Thanks for thinking of me Ross! It has been so cold here in Central PA I only worked on it once since my last post.

I had my son crank the engine with a breaker bar while I had my finger on the eccentric. It turned with the cam. I had my son push the starter button while I shone a light into the fuel pump hole and I could see the eccentric turning. I of put my finger in there while he was cranking the engine with the starter button but I chickened after a second or two as I envisioned my finger getting chewed up with the timing chain. I tried the stick idea but could not tell if the stick moved up and down or not.... so that was inconclusive. What I will do next is try to put the pump on again and see if it pumps gas out of the gas can.

And I might go down to my local garage and ask them for advice.

 

Prime it? Perhaps it was too high a "lift" for it to pull unprimed. Or, pinhole in feed hose.

 

OK, I am not sure how to prime the pump. Would that mean putting gas in the feed hose? Explain please.

 

Sure, actually just limiting the fuel's "lift" to a few inches until there's some fuel at the pump. I thought of this because my dry (electric) fuel pump wouldn't pull gas from a freshly-lined (just replaced) tank until I unfastened it from high on the fender and physically lowered it into the bottom of the engine bay. It's hard for a bone-dry pump to lift fuel very far.
You could get a funnel and pour some fuel into the hose to reach the inlet. Then crank it a bit to get the diaphragm wetted. It's just a theory.

 

Introduce air positive pressure into the fuel tank to force fuel out into the line. The pump is trying to create negative pressure by creating the vacuum to draw the fuel. Sucking fuel that far can take a while. Any pin hole in any line or hose between the tank and pump and the pump will never pull fuel.

 

NOTE: Unlike mechanical fuel pumps, electric fuel pumps are designed to push fuel, not pull it. They should always be mounted as close to the tank as possible, and below the tank pickup.
At this point my bet would be on a stuck or damaged check valve in the pump or a plugged fuel filter. Remove the fuel line at the carb and direct it into a quart jar. Remove the coil wire from the distributor so the engine can't start. Crank the engine over while watching the fuel delivered out the end of the line, it should be a fair amount at a significant pressure. Better yet use an inexpensive fuel pump pressure gauge attached to the fuel line to measure the actual pressure (Harbor Freight, combo pressure and vacuum gauge, 15.00). If the pressure and flow is low or non existent replace the pump. If it is good, check for a plugged filter in the carb.
Does your fuel line screw into a large thin nut at the carb? Does the carb casting have a cylindrical shaped swelling right after the nut? If so it likely has a sintered metal filter inside that swelling. After removing the fuel line, unscrew that large nut. Behind the nut (actually a plug) you will find a spring and a sparkly looking brass or copper colored metal filter element. Take the element to you local NAPA or other good parts store and match it to a new one. The old element may look clean, but is extremely fine and can plug up with invisible particles of varnish etc.

 

Abe, if you have small stones in your gas tank they can act like ball-valves and still allow some gas through. A stone ball-valve would also allow back-flushed air to bubble in your tank.
I agree it's unlikely your eccentric is bad.
These old pumps create a lot of pressure as I found with my leaks. I think you have an obstruction.
-Wilson

 

Thanks for all your help. The response has been awesome! I haven't been working on it lately since it has been too cold here in central PA. Today it is snowing....

Here is the current status. To avoid or to rule out gas tank problems, or dirt in the line, etc I have removed the rubber line from the hard line. The outlet rubber line has been removed from the hard line going to the carb.

So, I might have a pinhole in the intake rubber tube as someone suggested above.. However, I have had the new pump in my hand, put the inline in the gas can, and manually pumped the fuel pump and it gushed out gas. So I think that would rule out pinholes in the rubber tube. I have visually checked both rubber lines and they look good. But when it is in place on the truck it will not pump.

My next idea is to put it on the truck again. But before I do, pump it manually to get gas "in the pump itself"; put it on the truck; pour gas in the in line and stick it in the gas can and hold the can about level with the pump so it doesn't have to pump it 'uphill'.
Any other ideas?

Will let you know my results if spring ever gets here!

 

Keep an appropriate extinguisher handy. It's easy to forget how volatile gasoline can be - even on a cold day.