MEP-016b / 701a - fuel draining back to tank overnight

[ssybert]

Hi Guys,

I'm wondering if anyone has seen this before. MEP-016b, fuel it up, new filters, etc.... Starts right up runs good. Shut it down and half a crank and it's running again. If I let it sit overnight, all the fuel in the filter housing has drained back to the fuel tank and starting it takes miltiple attempts, stalls, sputters, etc. It will start, but immediately stalls.

I'm wondering if the lift pump is breaking down and fuel is slowly seeping backwards through the pump? It seems if the generator sits for a couple hours it will still fire right up but overnight all the fuel has drained from the filter housing and it's tough to get running. Anyone seen this? Is there a rebuild kit available for these lift pumps or is my only option to upgrade to an electric pump?

Thanks,
Scott

 

[Isaac-1]

If it is draining air has to be getting into the system so you have a leak somewhere either the pump or in a fuel line.

 

[ssybert]

Well intitially that was what I was thinking, but then I thought, the system is open and air can always come in through the fuel return on the tank. My thinking was if the fuel pump had some internal failure, small enough not to cause running failures, the pressure of the fuel in the filter canister could push the fuel back down in to the tank and pull air back up the return line.

Does anyone know of these pumps are rebuildable of if diaphrams, etc are still available? Unless someone else has another suggestion, thats probably where I should start.

 

[storeman]

Have never toyed with that unit. I suspect the TM says there should be a check valve in-line to prevent that

 

[storeman]

I don't know squat about that unit but shouldn't there be a fuel line one-way check valve like in the 002's and 003's

 

[ETN550]

Both check valves in the transfer pump are leaking. Either replace or rebuild the transfer pump. Parts might be hard to find. The pump can be abandoned in place or removed and blocked off with a plate then use an electric pump. Run it off of the shutdown solenoid circuit. If it is doing this after sitting only a day or two it is leaking back pretty severely. The transfer pump has a rubber diaphram which may also crack over time and allow fuel into the oil which must be stopped. Pull the pump off and take it apart. There is always the possibility that dirt or varnish has it hanging up and maybe a good cleaning will fix it. Adding a good check valve to the discharge side of the line would also be a fix, but ultimately both pump checks need to work for it to move fuel properly.

 

[ssybert]

Hi Guys... Thank you all for your input. I've run in to this before and as ETN550 mentioned, just replaced the mechanical pump with an electric pump capping off the original with brass plugs. fortunately this one ended up just being a poorly seated filter housing gasket but I know there will be a next time. I tried calling Delks for a pump kit but William had no idea where to find such a thing. I'm going to try Cummins next. Very doubtful they are going to still have parts for these unless the pump is still used somewhere else.

Thanks again for confirming my suspissions.

Scott