Generator will not stay running

[Rusty Bear]

Originally Posted by dennismhamm

yes. fuel tank is full also just changed the oil fuel filter and air filter

Could be new fuel filter defective.

[Old Scout]

…...defective fuel filter???????--probably not.....need to keep looking.

[dennismhamm]

new fuel filter after it started it. still looking. at my sons now he's checking it out. we have checked all connections re tighten every connection and still no luck

[Jeep401]

Did you happen to clear the codes and start over to see if it's still the same?

Mine did this the other day after running under load for about five minutes but clears it self up after restarting a few time.

I still need to go back and look at and clear codes. I didn't find out that I pulled them wrong until after I had come back in the house for the day and it was running fine.

[dennismhamm]

not to sure how to clear codes?

[Bsipe01]

I've experienced problems when the tank goes between 1/2 & 1/4 & the genset shuts down. Have you re-primed thoroughly? If the engine kicks off but runs really rough & shuts down, it's probably fuel related. Since you mention filter in your post, and you're describing what sounds like fuel starving, I'd focus on priming thoroughly. AFAIK, the control module will time out if you prime it too long (I believe 3 mins), but other than that, there shouldn't be an issue. Time it, 3 minutes is a LONG time. No fuel, no joy. Good luck!

[Jeep401]

Originally Posted by dennismhamm

not to sure how to clear codes?

Well I can't figure out how to give you a link to the PDF, sorry.
If you Google " Onan QD 7500 codes" a ton of info will come up including a PDF of the manual.

[Jeep401]

Originally Posted by Bsipe01

I've experienced problems when the tank goes between 1/2 & 1/4 & the genset shuts down. Have you re-primed thoroughly? If the engine kicks off but runs really rough & shuts down, it's probably fuel related. Since you mention filter in your post, and you're describing what sounds like fuel starving, I'd focus on priming thoroughly. AFAIK, the control module will time out if you prime it too long (I believe 3 mins), but other than that, there shouldn't be an issue. Time it, 3 minutes is a LONG time. No fuel, no joy. Good luck!

I felt mine was fuel related also. I could hear the pump prime so I figured the filter is getting plugged or had a air pocket.

[Jeep401]

Originally Posted by dennismhamm

not to sure how to clear codes?

If there are no lights flashing on your manual switch push it to prime 3 times within 5 seconds this will get it flashing if there are any codes.
Count the flashes, in my case it was three.
This only told me I had codes when I looked it up.
Now press the prime again 1 time, this should give you a set of flashes that you need to count. A number of flashes then a pause and a second number of flashes.
This will be your code to look up and start to troubleshoot.
Press the prime 2 times to clear the codes and attempt to run the generator again and see what codes if any come back up.
Clear as mud right..
Just remember 3,1,2
3 times to wake it up.
1 time to get code.
2 times to clear.
Hopefully this will give you a new starting point and also make sure you are not trying to troubleshoot for a random old code.

Hope this get you going in the right direction.

[Mile Marker 42]

Originally Posted by dennismhamm

Gen 7500 diesel will fire up and run for about 5 seconds then shuts down. I have changed the temp sensor but did not help at all. If anyone has any info your help will be most appreciated. Thank you in advance.

Had a very similar issue with my 7500 QD with I believe the same code. My issue was, it would run 5 mins then shut down. All the basics were fine such as oil, coolant level etc. Someone here mentioned that in the aviation business, they disconnect power to a plane to clear codes. He suggested I do the same, and it actually worked for me. What I did was: disconnect both power cables underneath from the generator for 30 mins. While disconnected I wire brushed both cable ends and the mounting studs they go to. They usually have a bit of corrosion there. Then, connect them back up. Hold the generator button down for 60 seconds. After 60 seconds, start generator. Honestly, this worked for my issue. Might be worth a shot on yours, unless you already had these disconnected to replace your sensor.

[Old Scout]

….you can also hold down the on/off switch on the genset [not the cabinet or dash] in the off position to manually prime the pump/engine.....while running, the pump sound should change pitch when a good prime has been achieved....

[wolfe10]

Originally Posted by Old Scout

the pump sound should change pitch when a good prime has been achieved....

Yup, fuel pump speed/RPM higher pumping AIR. Once it pumps fuel, it will slow down/RPM will be lower.

[DrDaveMA]

Since you stated you just changed the fuel and air filters the first thing I would do is park my finger on the stop side of the start/stop switch for AT LEAST 3 minutes, while doing that listen to the fuel pump to see if the sound changes. This will prime the fuel system (in other words fill the new fuel filter). If that does not get it started read the error codes.

[Coach nut]

I had a similar problem run for 2 mins and stop ? It was fuel pump worn out ! Disconnect hose to carb and prime with switch and check flow! Hope that helps?