Onan Gold Marquis 5500 gas stops after 3-5 minutes

[smerrett]

Hello members. my Onan gold Marquis 5500 generator stops after 3-5 minutes from what I believe to be fuel starvation. It sometimes report failure code 36. I have replaced both fuel filters, spark plugs, air filter and even changed the oil. The fuel pump seems to stop after a while. Should the low pressure pump be running all the time while the generator is running or only when the fuel pressure drops. I did a test and connected the fuel pump directly while running the generator and confirmed the pump stops. After waiting 4-5 minutes, Im able to restart the pump. I tested running the pump into a jar (no pressure) and it ran for more then 10 minutes. After putting some significant restriction, it stop maybe 2 or 3 minutes after. So, the question is, should the pump be running all the time even when there is enough pressure? Thanks

steph

[Jim_HiTek]

I've read about this type of failure and most suggest that you check your gas cap for proper venting. If it's not venting, the gen becomes starved for fuel and dies.

Pretty sure that the pump runs all the time.

[ChuckinKC]

I had a similar problem that in my case turned out to be a 12 volt power problem. The voltage from the house batteries would drop down below 9 volts and the fuel pump would stop pumping, and very shortly thereafter, the gen set died of fuel starvation. That is such a weird problem that it is probably not what is happening to you, but you might check it out.

[LSU Tiger]

I had the same problem a couple of years ago and the culprit was a hole in the fuel line to the generator. It happened when we were crossing Texas with 100 plus degree heat. The fuel line had rubbed a hole where it crossed one of the frame members. Good luck with the problem