My Willys 3A and 3B Community
TECH FAQ SECTIONS => Engine compartment => Topic started by: Don_Parrish on March 17, 2023, 03:35:24 PM
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CJ3A with F engine. Removed old pump due to contamination. Prior to contamination the pump had performed well. Ordered and installed "new" pump...no fuel flow. Pump source acknowledged the problem and supplied a second pump. Installed...same result...no fuel. Fuel line from tank flows well when held low enough for gravity feed. Pump to carb line blows free. Two bad pumps in a row? I feel I may be doing something wrong. But what? Finger checking the suck side of the pump seems to indicate "pull" but the only test I find is gauge with engine running. No fuel to carb...no run.
Any thoughts would be appreciated.
Don Parrish Phoenix
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All fuel line connections need to be tight. Any rubber to straight-cut steel connection needs two full-wrap (NOT worm-drive) clamps. NAPA has them.
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Don,
I would suspect some vacuum while cranking if the arm is contacting the lobe. Do you have the dual pump (w/ vacuum)? Are the original and replacement the same type?
If you know the original worked, have you considered getting it rebuilt?
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Scout: No rubber to straight steel. Two barbs to rubber with one each worm clamp.
Rus C.: Not dual action pump. The old pump seems trash and leads to where can I find someone to overhaul. The two "new" pumps are identical to the old. Have not opened to inspect the
interior parts.
Note in Passing: As I have attempted to work this, it was suggested to pressurize the fuel tank slightly. I rigged a rubber cap for the tank and was able to hold a low pressure for a couple of
minutes as I cranked the engine. There was still no flow from the fuel pump.
As I have read through some of the problems with fuel and carbs, the term "chicom pump" is used. I'm thinking perhaps I am a victim of just that. Is there a reliable source
for the "real thing"?
Not of significance here, but I'm about to install a Chicom distributor on my 50's Ford tractor. This fuel pump thing isn't giving me much hope.
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I didn't know Rick (Scoutpilot) before I got my pump restored. He's advertised and runs his own forum:
https://oldjeepcarbs.freeforums.net/
https://www.facebook.com/oldjeepcarbs/
He has fixed me up on a few annoying speed bumps along my rebuild process. If y'all do some PM's, I'm sure he'll be able to sort out your original pump.
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Hi, I suggest you test the pump out of the car, attach a hose to the inlet, put it in some fuel or water and hand crank it.
You should be able to blow through the pump from the inlet side, or suck from the outlet. You should not be able to do it the other way, if you can it's the check valves failing.
If it works then either the arm is too short, due to a spacer between the pump and the block preventing a full stroke or the carb float valve is locked shut.
Good luck.
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I didn't know Rick (Scoutpilot) before I got my pump restored. He's advertised and runs his own forum:
https://oldjeepcarbs.freeforums.net/
https://www.facebook.com/oldjeepcarbs/
He has fixed me up on a few annoying speed bumps along my rebuild process. If y'all do some PM's, I'm sure he'll be able to sort out your original pump.
rick re did my dual pump fuel /air . works great. would use him again for sure