willysmjeeps.com

Hey guys.. I have been slowly bugging the fine folks over at g503, but I thought I'd spread the pain a little.

The truck is a 51 m38, factory block. It was running I took the fuel pump off and sent it away to have it rebuilt.

Success on that front.

However, now that it's returned, I can't get it back on!

It is a pump from an A1 motor as best I can tell (it has a mechanical primer lever). I am using a (about) half inch spacer and 2 gaskets and basically.. it just won't go on.

I have 2 other pumps. One from a Civ motor and one, that I assume is an original pump. And both bolt right on.

The one that I think is an original uses a tiny (1/8th inch or so) metal spacer and the civ one uses no spacer at all.

The only difference I can tell is that the A1 pump has a different cant to the actuator foot. But either way.. it came off this motor and was running before the rebuild!

I am clearly not connecting some dots here.. but I can't figure out where I went wrong.

Any thoughts? All I can figure at the moment is I have the wrong spacer or possibly need another smaller one.. which doesn't seem quite right.

thanks folks.

Oh.. I have made sure that the cam lobe was at a low point or at least away from the actuator lever, and I made sure the pump actually moves. Which is does pretty easily, and travels about 1/2", if memory serves.

The fuel pump after a rebuild can be difficult to attach, new springs make it stiffer.

Try using some longer bolts to get it started and slowly pull it into position... then replace one bolt at a time to original...

You are going to want to use the thick 1/2" spacer...

Hope this helps...

Turns out that DID help. I thought the easy free travel distance was the pumping distance, but in fact after this distance it gets VERY hard to push by hand. Once I proved this to myself I forced the pump on with the bolts and she appears to work. At least with my fingers over the ports.

Thanks!