Fuel Pump Won't Prime, hitting the tank fixes it??

Today after class I went to start the Jeep and it wouldnt prime the fuel pump, needless to say it didnt start. After I got out and hit the tank a few times, it finally primed and started. Later, when I went to leave for work, the same thing happened, I had to hit the tank with my fist to get the pump to prime, and work.

Why does it do this? If there was a bad/loose connection, wouldnt the pump cut out while im driving? I have no driveablility problems once I get it running, but it takes hitting on the tank to get it to work.

Pump is a 2 year old Robert Bosch.

Thanks for any help.

pump might be starting to get gummed up

Jeepm@n said:

Is the pump running before you hit the tank? If that's the case clean your electrical connectors on the sending unit. If it's running and takes hitting it to get it to suck fuel I'd bet your regulator is allowing the fuel to leak back into the tank thus causing an air pocket when sitting.​

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No, once I hit the tank, then it will prime.

Thinkin I need a new pump now...

id say go with a new one
i got a new pump from napa for my 96
it was $130
i hope to get mine running tomorrow at school