Fuel Pump?

[Joopin]

So...
I finally finish my drum to disk swap on my 91 YJ... finished the day off bleeding the brakes and driving it around the lawn to test the new brakes.
Shut off the jeep and bled the brakes again...

...Wouldn't start again! Just kept cranking, almost like it was out of gas. It sputtered a couple times, then would do nothing. I took that cap off the fuel rail (it's fuel injected) and nothing was coming out or spraying or anything. Not to mention the fuel rail hoses would squeeze down easily... like nothing was in it.

I think it's the fuel pump, but I just wanted to get others opinions...
I did check the EFI fuse and relay, both seem to be good.

So what do you think? I gotta start this so I can test the new brakes!

 

[SteelHeadz]

I think your in the right track Jesse. Just to verify the condition, i would put a test light on the fuel pump circuit and turn the ignition on and see if the battery voltage is actually evident on the fuel pump connector.

 

[Joopin]

I think your in the right track Jesse. Just to verify the condition, i would put a test light on the fuel pump circuit and turn the ignition on and see if the battery voltage is actually evident on the fuel pump connector.

in the fuse box? is there one labeled fuel pump? if so, I missed it. I also read in my chiltons to get a "fuel pressure regulator" and check it with that.

I found out that the pump is in the gas tank... I can't imagine replacing it being an easy job.

 

[SteelHeadz]

I would think that a fuel pressure gauge would be a waste of your time since you verified that there's no fuel on the injector lines. I would trace out the wire on the fuel pump module and check for battery voltage from there. There should be a harness that runs from the front driver going to the rear of the body that has the circuit your looking for. I don't have a manual here at home so your best bet right now is that Chiltons wiring diagram you have.

 

[Joopin]

It ended up being a broken hose inside the gas tank... the pump was working but the hole in the hose caused the pump to pump gas back into the tank!

The reason it happened? I had the jeep jacked up working on the brakes at a freinds house, 2 days of rain softened the ground and the jack stands sunk in. The jeep fell and one jack stand was under the tank. So I think the tank was pushed up, causing the fuel pump bracket to bend and pierce the hose, so I had to drop the tank for a 4 cent piece of hose... oh and the gas tank skid is now garbage...

...just my luck.

 

[yo momma yj]

FWIW...if you chronicly run the tank way low the fuel pump ground wire can heat up and break...which acts like a bad pump.

don't ask me how I know this...

keep a 1/4 tank of fuel to keep the thing cool and pump submersed.

I think it's a stupid design flaw.