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My 360 keeps going through fuel pumps. I've been through 4 in the past 6 months. One was on for over 10 years before it went out. Replaced pump with one from O'Reillys which went out about a month later. Replaced that one with another O'Reilly one and put a filter before the pump and replaced strainer in tank because a bunch of dirt and stuff came out of the pump. Last week it went out again and I replaced with a Delphi pump. That pump just went today.

Could the filter before the pump be causing my issues?

Thanks

Clean the tank? Check the fuel lines to make sure they are not deteriorating and particles from the hose are clogging the pump?


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I know the tank is filthy and the rubber lines on the tank are crap but shouldn't the new strainer and the filter be getting all the gunk?

I'm just speculating but since the mechanical pump uses a diaphragm, how much blockage would cause the pump to fail? Sounds like cleaning your tank and replacing the lines is your best start.


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How are pumps failing? Leaking? or failure to pump fuel?

I had a filter before my pump and it worked fine. I finally when with a electric pump to get rid of the vapor lock issue.

kansasboy001 wrote:I know the tank is filthy and the rubber lines on the tank are crap but shouldn't the new strainer and the filter be getting all the gunk?

Is the pump not pumping or does fuel pour out of it? If there is nothing coming out then it's quite possible the strainer AND the filter are simply clogged and there isn't anything wrong with the pump. You can try disconnecting the metal line just before it goes into the pump and make a line to go into a container of gas. Disconnect the out put line and loop that back into the same container. If it moves fuel it is fine. Time to clean the tank etc. When my new (less than 20 miles on it) pump stopped I blew air back through the metal line. Heard it pressurize then heard a pfsst as the air escaped. Turned out the rubber line off the sending unit was so deteriorated that it fell apart. The mechanical pump doesn't generate enough pressure to pull fuel with a gaping air leak in the line.


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I went electric a year ago because of the same issue--failing mechanical pumps. I believe its the poor quality of the reproduction units. However, guys on this site provided a link to a performance Carter pump that may be better than the junk that the Box stores are selling. The Holley Red top has worked great for me with faster starts and no vapor-lock issues.

The pumps simply stop pumping properly. They pump a very small amount of gas barely pump at all. I've never had a pump leak.

I had some grumbling times with mechanical pumps a few years ago. Part of what I found was the castings are much thinner on all the brands I looked at. A pump that has been around for a while is thicker and I believe this dissipates more heat. The first one I ended up hating with a passion would vaporlock at 7000' on a 85* day. I really believe in electric but have had different issues with different brands of those as well. I have seen red tops poop the bed too. Debris in your fuel can make for a grumpy day. Jeeps are just a collection of rented parts. When the rent contract expires, time to negotiate another rental, ie - more parts.

fulsizjeep wrote:I had some grumbling times with mechanical pumps a few years ago. Part of what I found was the castings are much thinner on all the brands I looked at. A pump that has been around for a while is thicker and I believe this dissipates more heat. The first one I ended up hating with a passion would vaporlock at 7000 on a 85* day. I really believe in electric but have had different issues with different brands of those as well. I have seen red tops poop the bed too. Debris in your fuel can make for a grumpy day. Jeeps are just a collection of rented parts. When the rent contract expires, time to negotiate another rental, ie - more parts.

The Delphi definitely has a thicker wall than the O'Reilly one which might have been made by Carter as it had m6736 stamped on the side. I've never had a vaporlock problem. Mechanical has worked fine.

BTW is there a way to replace the rubber hoses without dropping the tank. I do have the access panel on my 83

I think the hose job goes better if you drop the tank. I don't enjoy dropping them. Depends on your preference if you have the access panel.

I wonder if the fuel pump eccentric on the cam is worn, not allowing enough movement of the pump arm? I've seen it on cams where the eccentric was part of the cam casting, not sure it can happen on a FSJ design. Easy enough to check, remove pump, get a mirror and flashlight to see inside the timing cover.

Curly wrote:I wonder if the fuel pump eccentric on the cam is worn, not allowing enough movement of the pump arm? I've seen it on cams where the eccentric was part of the cam casting, not sure it can happen on a FSJ design. Easy enough to check, remove pump, get a mirror and flashlight to see inside the timing cover.

Wouldn't that cause the pump to constantly not pump enough? When a new pump is on it pumps like a champ.

You can change some of the lines without dropping the tank but it sounds like you need to drop it and clean it anyway.
To half-ass it, remove the access panel under the rear seat. You'll see the top of the sending unit with two wires and two fuel hoses. The larger is the feed and smaller the return line. They may have the original pinch band clamps on them if it's never been tended to. Those hoses are less than 2' long and run towards the back of the tank and tie into the metal lines that run inside the frame towards the motor. You can change them with a little finagling without dropping the tank.

Don't be too surprised if the other rubber parts for the fuel are tired too. The roll over check valves are two culprits as well but they require the tank to be dropped.

kansasboy001 wrote:

Curly wrote:I wonder if the fuel pump eccentric on the cam is worn, not allowing enough movement of the pump arm? I've seen it on cams where the eccentric was part of the cam casting, not sure it can happen on a FSJ design. Easy enough to check, remove pump, get a mirror and flashlight to see inside the timing cover.

Wouldn't that cause the pump to constantly not pump enough? When a new pump is on it pumps like a champ.

You are probably right, just throwing ideas out. Next time you have the pump out, you can check.

Curly

That could be a problem too. When I replaced my tank lines they where porous and leaked so I figured they would suck air too. It help some, but I still had a vapor lock problem.

Thanks for all your help. Turned out to be rotting rubber lines by the tank as well as my inline filter was in a bad place. Would get an air bubble then would stop flowing.

My rollover check valves are leaking as well so later when I have the time will be dropping the tank.

Rotting fuel lines are the work of satan.