Fuel pump not working?

So I’m assuming my pump went out but maybe I’m wrong. Jeep fired right up I drove it about a mile down the road to the gas station. Filled up a gas can and started it to head home and as soon as I pushed the gas pedal it does. I notice the fuel filter is near empty. It won’t start, I pulled the air vent off the top of the carb and put my hand over it to create suction hoping to get the fuel moving. The auction fills up the filter and the jeep will start and run and then I watched the fuel slowly drain back down out of the filter towards the pump and the jeep of course then dies. I see zero leaks anywhere, no puddles under the jeep. Am I right to assume something is wrong with the fuel pump?

How would I test that? After my last post I discovered that once I get fuel flowing if I keep my hand on top of the carb, let air flow but not fully open so I cover but with a small gap it will remain running. As soon as I remove my hand a few seconds later it begins to stop flowing, the fuel drains back towards the pump and then dies.

I would pull the fuel hose loose from the carb and see if the pump pushes fuel out when the engine is cranked. 

Ok sorry if this is a dumb question but I just want to make sure I understand. So there’s a vent on the fuel cap as in the one I remove to put fuel in the tank?

Huh that makes sense. Thanks I’ll give it a try in the morning and hopefully it’s just that simple

Well it’s not the fuel cap. That didn’t make a difference at all. The only way to get fuel moving is by creating a suction from the top of the carb. That sucks fuel into the lines and then as soon as that’s removed it starts draining back the other way. Gotta be the pump right?

Edited by Ron D - 21 Aug. 2022 at 2:14pm

I wish we could "like" posts on this board. I wouldn't make nearly as many replies!

But I would like to point out Ron is offering some essential lessons in troubleshooting (whether it's cars or software or old radios or whatever) in his two posts.

I would also add an observation: do the volume test first. It is rare (but not impossible) to have a pump that can provide the correct volume but not enough pressure. Doing the volume test does not require a specialized gauge although it does require care not to set the car on fire. Keep the gas away from the exhaust manifold.



Edited by CJ2A60 - 22 Aug. 2022 at 11:03am

Joe Friday wrote: Hand over the carburetor? Is that called a choke?

Down south they call that “Hand Gagging”

Lee