Onan generator running problems.

[Heinz Gee]

I have a Onan HDKAK 8000 generator that will initially start and run for approximately one hour an then stop. I will restart right away but only run for about three minutes, stop, restart and run for about one minute. If it rests overnight it will go to the same process again.. I have checked the following: Replaced fuel filter, checked incoming voltage, checked fuel line,and air filter. When it stops it does NOT show a code. What I missed?
Any help will be appreciated.

Thank you,

Heinz Gee

[jondrew55]

How much fuel in your tank? Most MHs have a separate fuel line for the generator that won't stay fuel around 1/4 tank

[Jamie65]

Follow the fuel line, pull the generator out if possible and look for an in line fuel filter.
Many Manufacturers add a second in line filter before the generator. I had the same problem, traced the fuel line from the generator back and found and replaced the filter. It is a common filter usually 1/4" , most any auto parts store will have one, just ask for an in line 1/4" diesel fuel filter NAPA # 3031.

[ShapeShifter]

Have you checked the condition of the coolant and cooling system recently? It sounds like it could be a temperature related condition: after an hour it gets hot enough that something is cutting out (although not the typical temperature sensor, as that would report a fault code.) When you try to restart right away, it cuts out soon because it's still hot. After cooling overnight, it runs longer because it takes longer to get to the critical temperature.

I don't know what could be overheating and causing it to stop, but it could be a potential cause?

[Duoglide1]

Mine was showing the overheat codes and doing the same. Many $ thrown at it and turned out to be a bad coolant cap. Took a long time in the shop with new radiator, sensors etc but that turned out to be it. Unless yours is new it may be a cheap fix.


2005 Country Coach Inspire, C9 CAT

[MSHappyCampers]

You didn't mention checking the oil! If it's low it will either not start, or start and run for a short time, then cut off.

[gypsyduo]

we just bought an 1987 Winnebago. The converter doesn't seem to be charging the house batteries (deep cycle). The onan emerald 1 gent set doesn't start. And my dog bit me-lol. Could these two be related? When I plugged into house receptacle, I got zero amps across the house batteries leads. Also, the owner's manual says I should not run the gen set with both batteries connected. Does it mean the starting battery should be disconnected? Any tips are appreciated.

[mus289]

Heinz Gee, I went through the same symptoms with my gas Onan 5500 last summer. If you are in a hot climate in particular and have done all of the other "normal" tests. Consider replacing the fuel pump. I read a number of blogs and finally 1 guy had gone to an Onan repair shop. They said the windings in the pump motors weaken with age and particularly when it is extremely hot they slowly lose power while running until they wont pump enough fuel. He watched their amp meter show fewer amps until genset stopped. I took a chance, replaced my fuel pump and Voila, has run great since even in Fla summer heat! One mans opinion and result. Diesel or gas the pumps do the same job. Good Luck!

[Barlow46]

delete.

[gypsyduo]

Hey people, gypsy duo here with another problem. My onan emerald I generator is finally starting up and running. The previous owner banged the muffler pretty hard and cracked the connecting pipe completely though. I puttied the two parts together and it is running a lot quieter. It doesn't charge the batteries however. If any of you can help with this, I would appreciate it. It must be something trivial because all my other problems with this 1987 Winnebago thus far has been trivial, touch wood. I also would like to know how to get the owner's manual for this. The others I have downloaded don't seem to be the right ones. Thank-you all for your previous help.

[Iwillbeit]

I too have the exact same generator and had a very similar problem. My problem turned out to be the fuel line. The line had a sweeping curve in order to connect up to the filter. The fuel line was kinked restricting the fuel flow. The generator would run for about an hour or less if I put a heavy load on it and shut off. It would instantly start back up and quit within a minute. If it set for awhile, it would run awhile. To fix the problem, I removed the filter and was able to straighten out the fuel line... Fixed my problem and it never quit again ... I hope this helps


Randy W

[Iwillbeit]

Originally Posted by Heinz Gee

I have a Onan HDKAK 8000 generator that will initially start and run for approximately one hour an then stop. I will restart right away but only run for about three minutes, stop, restart and run for about one minute. If it rests overnight it will go to the same process again.. I have checked the following: Replaced fuel filter, checked incoming voltage, checked fuel line,and air filter. When it stops it does NOT show a code. What I missed?

Any help will be appreciated.



Thank you,



Heinz Gee

I too have the exact same generator and had a very similar problem. My problem turned out to be the fuel line. The line had a sweeping curve in order to connect up to the filter. The fuel line was kinked restricting the fuel flow. The generator would run for about an hour or less if I put a heavy load on it and shut off. It would instantly start back up and quit within a minute. If it set for awhile, it would run awhile. To fix the problem, I removed the filter and was able to straighten out the fuel line... Fixed my problem and it never quit again ... I hope this helps



Randy W


Randy W

[Rich-n-Linda]

It's overheating.


2006 Mandalay 40E, Cummins ISL 400 HP

[Iwillbeit]

Originally Posted by Rich-n-Linda

It's overheating.


2006 Mandalay 40E, Cummins ISL 400 HP

Maybe, but overheating usually gives an diagnostic code.


Randy W