Fuel Pump Lever Travel

I have a ‘66 134F that had an electric pump installed when I bought it. I’ve disconnected it and installed the OEM mechanical pump. When I crank the engine, I can see some fuel going into the bowl but it never fills. When I removed the pump and actuated it by hand, it pumped fuel just fine. Is there a different pump that requires less lift from the cam lobe or is it likely that I have a flat fuel pump cam lobe?

 

Welcome from Michigan. There is a lot of conversations about fuel pumps, some have a spacer between the block and fuel pump to regulate the pressure. What I am saying , I guess, is you need to check what the pressure is to know, too high and it will flood the carb, chances of a bad lobe is pretty slim. Good Luck.

 

This.

If it seems like the pump has more air than gas in it, check connections for a suction leak in the fuel line from the tank.

 

Out of curiosity, is it a single action (fuel only) or a double action (fuel and vacuum)?

 

It’s a rebuilt single action pump. I’m currently running a 3’ hose into a container with gas. When I turn the engine over it’s actuating the diaphragm, but it doesn’t act like it’s getting enough travel to pump the gas. When I pull it off the engine and actuate it by hand, it pumps just fine. I even compared the drive lever to the original pump and it’s the same, which makes me wonder if that’s why the electric pump was on there to begin with. Either way, I recently bought two spare parts CJ5’s and one of them had a complete rebuild kit for the 134 with it, so I’m probably about to pull the engine and rebuild it. I’ll put a dial indicator on the pump cam lobe and check it when I get it out, I believe I read somewhere that it was a .160 lift on the pump lobe. Thanks for the help, fellas- I’m sure this won’t be my last inquiry.

 

Did you rebuild the pump?

 

Yeah, define"rebuilt."

Air leaks commonly happen at the pump cover gasket, BTW.

 

Rebuilt from KaiserWillys.com

it works fine when hand actuated, that’s what makes me think it’s the cam lobe.
I appreciate all the responses. When I have time to tear into it, I’ll share more info.

 

Please post a photo of this single-action pump. I assume from your stated observation of the pump that it has a glass bowl on top. Please tell us this bowl is not one with a divider in the middle and does not have four valves.

 

It does have the divided bowl. I assume that’s a bad thing, lol?

 

Yes. It is. Unless the alignment of the bowl and the gasket are perfect you'll have issues. BTW, I've never seen a rebuild kit for this design. If it was rebuilt, which I doubt, the job was not done correctly. Were I in your spot, I would seriously consider acquiring a proper OEM fuel/vacuum pump.

 

The pump works fine when hand actuated, that’s why I’m leaning towards something other than the functionality of the pump: either a flat cam lobe or perhaps a mismatched spec of travel required to operate the pump

 

I will guarantee you the pump arm will wear faster and more than the cam lobe.

 

My bet is the pump is garbage. Just went through two and the third was good carter pumps also