Never mind. I found it......Onan 8k fuel pump testing procedure ?

[411jeff]

Never mind. I found the procedure.




I can't seem to find this online.

What is the procedure to test the fuel pump output on a diesel Onan generator?
I did it about 10 years ago, but I can't find the procedure now.
I know I need to disconnect the line out of the pump and see how much fuel I capture but I forgot the details like how much fuel over what amount of time.


Thanks.

[NLOVNIT]

Well, don't keep it a secret. Someone else may want to know & if you post where you found it, that'd be a real nice thing to do. It's what a forum is for.

[jacwjames]

In May my wife was a trip, going to a dog show in ILL with her dogs. So she needed the generator running. I did a full service before she left and all was good.

Second day of her trip the generator would not start, show a code 3. I walked her through on how to change the fuel filter. That didn't fix it. I could hear the pump running but it didn't seem to be loading up.

So I made arrangements for her to take the coach to the Cummins shop in Normal ILL. Explained she was on the road with dogs and needed the generator, the service writer understood and agreed to look at first thing in the AM, said just bring the coach in and she'd put a tech right on it. I told the service writer that I thought it was a fuel delivery problem.
She got to the shop and the tech got right on it. He also thought fuel issue so he brought out a small fuel tank and hooked it up to the pump, still wouldn't start so he said it was the pump.

Replaced it and got the generator running, let it run for ~1/2 hour. Cost of the pump was +$250 and the labor was $600. So $850, but I can't complain, they got the thing running and my wife was on the road in ~2.5 hours.

[411jeff]

Sorry - Here is the old post I found when I did it back in 2014..


Fuel Flow Test
1. Disconnect the fuel return hose from the line to the supply tank and point the end into a quart (1 liter) or larger container that has volume
graduations.

2. Prime the genset by pushing the Start/Stop switch to STOP and holding it there for the duration of the test. Flow should not be less than 200 ml (0.4 pints) per minute.

3. If flow is less than specified, replace the fuel filter. If that does not help, look for other restrictions in the fuel system. Last, replace the fuel
pump. The pump is not serviceable



Credit goes to IRV2 user 94-Newmar