generator issues

[brianseay1]

I have an Onan 7500 super quite diesel generator that will not stay running. It will start with no problem, but it will run for about a minute and then die. But it will start right back up and run again for the same amount of time. After about 8-9 starts it did stay running for about 20-25 minutes and then died again. started it right back up and it ran for about a minute and died, done this several times. It has a new fuel filter and the fuel in it was put in back in march. I always park it on a full tank. The coach engine runs just fine and they both run off the same fuel system. I have a small video of what it is doing. The sound is very loud but you can hear me start it, ear it running and hear it die. And then hear me restart it. I can't figure out how to download the video though.Any help is greatly appreciated.

[brianseay1]

Ok a new update. After checking it out today, when I started it the first time without a load and it ran about 45 seconds and died and threw the code 3-27 again. I started it right back up and put it under a load right off and it ran fine. after about 20 minutes I turned the AC off and it ran fine. So what I am seeing is it runs fine under a load but dies without a load. Now I am scratching my head on this one !!!

[brianseay1]

Well after fooling with it today trying to get some ideas on what to check I finally got it to run. It had been plugged in to shore power all winter long and I know I have ran the generator with it being plugged in with no issues. Well today after fooling with it, I decided to unplug it and see what would happen. Well it took off like a champ and ran just fine for over 3 hours under a load. I finally shut it down and plan on trying it again tomorrow just to see what it does. Not sure why it being plugged in would matter, but apparently is did. Just wondering if I may have a switch or something going bad. If anyone hs any ideas please pass them along. Thanks.

[brianseay1]

brianseay1 wrote:

Ranger Smith wrote:

brianseay1 wrote:
It’s not throwing a code that I know of. Nothing comes up on the dash when it dies.

Code would be flashing lights on the start switch light

Ok, it is throwing a code then. I noticed the start button light flashing but didn't realize that's what it was doing. Where can a find a copy of what the codes are ? I just thought it was flashing like it does when the injectors are pre-heating for start up.

Ok I finally got to check it out this morning. The code it is throwing is 3-27

3-service fault
27-voltage sense fault
Controller unable to sense output voltage

the troubleshooting guide says see an authorized Onan dealer. Is this something I could possibly fix ? any help is greatly appreciated

[brianseay1]

wa8yxm wrote:
:That is a classic symptom of clogged filter,, Need more info to decide if air or fuel. Or a collapsed fuel line.

What more info do you need ? I will try to answer your question. Thanks

[brianseay1]

Ranger Smith wrote:

brianseay1 wrote:
It’s not throwing a code that I know of. Nothing comes up on the dash when it dies.

Code would be flashing lights on the start switch light

Ok, it is throwing a code then. I noticed the start button light flashing but didn't realize that's what it was doing. Where can a find a copy of what the codes are ? I just thought it was flashing like it does when the injectors are pre-heating for start up.

[Ranger_Smith]

brianseay1 wrote:
It’s not throwing a code that I know of. Nothing comes up on the dash when it dies.

Code would be flashing lights on the start switch light

[wa8yxm]

:That is a classic symptom of clogged filter,, Need more info to decide if air or fuel. Or a collapsed fuel line.

[ROBERTSUNRUS]

🙂 Hi, low oil?????

[brianseay1]

It’s not throwing a code that I know of. Nothing comes up on the dash when it dies.

[jdc1]

Disconnect the fuel pump and see what pressure it's putting out.

[Ranger_Smith]

2oldman wrote:
Perhaps your generator's carburetor is quiet gummed up.

Diesel generator . . . No Carb. What is it throwing for a code. Sounds like it is maybe sucking air from somewhere or bad low oil pressure cutoff switch.

[brianseay1]

It’s a diesel generator.

[2oldman]

Perhaps your generator's carburetor is quiet gummed up.