Fuel Pump Issues

[billyocup]

I tried firing my 75 CJ5 today (after I solved my ring gear issue). First off, every part of the fuel system is new, except the fuel pump and it was nearly new when I started my rebuild 20 months ago.

Poured a little fuel in the carb, cranked it over a couple of times and it fired right up. It ran for a few seconds then died. We did this several times, thinking it would take some time to get the fuel sucked from the tank up to the pump and then on to the carb. After about 5 or 6 tries, we pulled the fuel line off the carb and turned the engine over for maybe 15 seconds and no fuel to the carb. We manually sucked fuel from the tank up to the fuel pump, thinking that the pump might be having trouble filling an empty line. No help. My neighbor, who was helping me, went and got his fuel pump testing gauge, which measures both pressure and vacuum. We attached it to the inlet side of the fuel pump and cranked the engine over for 15 -20 seconds. The gauge showed no reading.

So can a fuel pump fail from just sitting? Could I have installed it wrong? I know it has an arm that rides on a lobe and the arm is suppose to go under the lobe. Doesn't seem like it would even go into place if the arm was in the wrong position. Any suggestions would be appreciated, cause I'm kind of out of ideas.

Thanks, Bill

 

[jamie]

the fuel pump will go in without the pushrod on the cam lobe, but its kinda hard to do that. its more likely the diaphragm in the fuel pump dried up and cracked, causing no suction. i would buy a new pump and a clear fuel filter to place near the carb and you will see the gas flowing if all is working correctly.

 

[JR74CJ5]

Posted in your build thread...

I did install the pump incorrect... It can happen, and sounded just as you describe...

But I am not positive thats your problem, just a thought in case you'd like to try instead of new pump right away route...


~ JR

 

[jasonmark1993]

Typically you have to install the pump low to get the shaft under the lobe, then to get the bolt holes lined up you kinda have to lift the pump up.

 

[billyocup]

I pulled the pump off this morning and it was installed correctly. I took the pump down to my local NAPA and had Tim look at it. He said it wasn't working correctly and ordered a new one that will be here tomorrow.