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SPShull · 09-03-2013, 05:27 AM

Just got my 2000 monaco motorhome w/ cummins 350, when it quit running. After I parked on the driveway facing slightly downward it felt like it ran out of fuel. Generator quit too. I was low on fuel but, gauge said it still had a quarter tank. I added 18 gallons. I removed both fuel filters one was full while the other was almost empty. I filled it up with diesel and the coach restarted then died. After pulling the filter it was empty again. Is this a fuse problem or fuel pump. Any help would be appreciated.

danes-on-tour · 09-03-2013, 06:55 AM

Once your fuel filters goes empty, you will not be able to just add fuel to the tank and start it up "just like that". Filters need to be full first. I know this from when I first started changing fuel filters.

In theory you should be able to fill the filters by priming the engine. Put the key in the ignition and turn it to where the fuel pump starts, but don't crank the engine. After about 20-25 seconds the fuel pump stops. Turn off the ignition and repeat say 5-6 times. This I believe is the recommended procedure.

In practice, I have found that this does not always work. Without wanting to start another argument with everybody else on the forum, I now pre-fill the filters and start-up is as easy as pie.

I am not saying that this is definitely your problem, but it very well could be that you have just run the system dry, and that once the filters and fuel lines are full again you may start it right up.

Good luck

deSanford · 09-03-2013, 07:28 AM

In the last "century" when we ran out of diesel fuel we had to crack open one of the fuel lines going to the injectors. The engine had a hand pump we pumped until the air gave way to liquid diesel. Motor started every time. deSanford PS today we use a Fass fuel lift pump, and follow the Danes recommendation.

AtlantaRick · 09-03-2013, 11:45 AM

I have had the same situation before. Turns out my lift pump (which is a separate pump from the regular fuel pump) does not work. The Cummins place said this is common. It is getting power but doesn't come on when you turn the key on. The cost of the pump and replacing it is about $300.00. Since it has only happened twice I am not going to replace it for now. My option if it happens again is to open one of the fuel inlets on top of the engine while someone cranks it and wait for all the air to come out of the line. They retighten the injector.

SPShull · 09-04-2013, 01:49 AM

I was able to re- prime the engine using you advice and now it runs great. Thank you.

danes-on-tour · 09-04-2013, 01:59 AM

Quote:

Originally Posted by SPShull

I was able to re- prime the engine using you advice and now it runs great. Thank you.

Thank you for the update - I am pleased that it turned out to a simple fix.

IRV2 rules

ShapeShifter · 09-04-2013, 06:34 AM

Quote:

Originally Posted by AtlantaRick

The cost of the pump and replacing it is about $300.00. Since it has only happened twice I am not going to replace it for now.

Might want to rethink that. I'm not an expert, but my understanding is that the lift pump is a low pressure pump that gets fuel from the tank to the engine where a high pressure pump then feeds the injectors. Without the lift pump, the other pump has to work harder and can get starved for fuel. When that happens it can get damaged, and it's a LOT more expensive to replace (1,200 to 2,000 sticks in my mind.)

This could easily turn into one of those pay me a little now, or a lot more later scenarios.

deSanford · 09-05-2013, 08:01 AM

Some of the benefits of the Fass Lift Pump is that it adds two more fuel filters to the system. Removes any "air" in the diesel fuel (caused by sloshing around in the fuel tank). Polishes the fuel as it is returning the excess fuel to the fuel tank etc. I have mine mounted back by the other Cummins fuel filters. deSanford