Generator Fuel Pump

Most likely you need to change the fuel filter. Change that first.

Your coach's fuel tank, sending unit and hoses are easily accessible from the driver's side. You have a "dead panel" (no latch on it) on both the driver's side and passenger side where your fuel fill doors are located. Those panels have two screws holding them closed at the bottom edge. If you look under the coach, you'll see the screws. Remove them and the entire panel, which is hinged at the top, will lift up. Use a broom handle to hold it open. Once the driver's side is open, you'll have access to the sending unit and fuel pick up tubes. You can inspect the hoses and connections.

Side Note: If you look at the sending unit, it's made by Centroid. It's adjustable. Most Monaco fuel gauges are never correct, usually they don't go to FULL, or more than half empty at the HALF point. There are a couple of adjustment screws to make changes. This is a topic for another time, but something you should be aware of. If you ever want to make the adjustment, PM me.

Centroid

Yeah, just a few days ago I filled up to the brim and immediately ran the gen. Easy start, 3 minutes, shutdown with 3-6.

Dave.....Just buy some fuel line that will fit the line on the generator. I would use a five gallon fuel jug since you say it will often run for two hours. This way to could run it for up to 8-10 hours. This may not be the fix, but if you're handy, it's a lot cheaper to eliminate some issues at home before spending $100.00 an hour. Make sure you put a load on it, like running the A/C.

Here's another thought and it may be hard to remember the circumstances. Over the years I remember some Monaco pick up tubes getting pinholes in them. Even though your tank may have enough diesel, the pinholes could be at the 3/4 or 1/2 mark. Have you ever run the generator with the main tank full to the top and had the issue.

It began to fail a few months ago, with a 3-6 code (unknown failure). Took it to a Cummins dealer who started it (after a hard start, as I remember), but it ran for two hours, with them starting and stopping it. Really nothing they could do. Afterwards I ran it myself, I think twice, for 2-3 hours each. Ran fine. Then the next time, ran for maybe 10 minutes, then shut down with a 3-6. Now it'll run for a couple of minutes and shut down, sometimes with a hard start, sometimes not. I've replaced the air filter, oil and oil filter, and I have lots of diesel. I do have 12 volts at the igniter thingies. The Cummins guys said there's not much to do but start tearing it apart and testing things, at $100+ per hour, and it could cost thousands.

When I inquire online about it, the most common response is something fuel related. So I thought I'd replace the fuel filter (looks pretty easy) and then think about doing the fuel pump. I see where it is; just not sure how to get to it. I may call or visit a local Cummins center and get advice.

What puzzles me is how it could run for 2-3 hours one time, and just 10 minutes the next. I could see a fuel pump becoming flakey and acting like that.

Ok, Don, I think I could pretty easily do that hose test. But use what hose? Just buy one that'l fit the input fitting on the back of the gen? Any specific type?

Thanks for any advice guys.

dave

As "Big Katuna" asked, what are the symptoms. You don't here about these going bad very often.

Remember, the pick up tube for your generator doesn't go as deep into the tank as the engine pick up tube, so that the generator doesn't run you out of fuel and leave you stranded.

Before replacing the pump, I would get a five gallon container of diesel fuel and run a hose form the generator into the fuel can and see if the generator runs normally. Often the OEM generator hose can go bad or the pick up tube in the tank have been known to get pin holes and cause issues.

Have you replaced the fuel filter and air filter?

What are the symptoms?

It may be a Airtex e11020 electric fuel pump... $60 many places and Amazon had them for $40. Electric fuel pump... Two hose connections, 1-2 bolts, and one wire. I would hope so.