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Topic: Onan 8K QD runs out of fuel (Read 1189 times) previous topic - next topic
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Onan 8K QD runs out of fuel

Yahoo Message Number: 115406
My generator will run out of fuel unless my fuel tank is full or nearly full. The first time it happened I was down about 65 gallons on a 100 gallon tank. After filling the tank it ran fine so I just thought maybe the generator fuel pickup is a bit higher than the normal 1/4 tank mark. This last time I was only 20 gallons down and it would not run. It started an ran about 2 minutes then stopped. The code was 36 which was the same as the other time it would not run. I filled the tank and now it runs fine. The filter is new. I wonder if it is the electric fuel pump at the generator not being able to lift the fuel.

Any suggestions as to where to look would be much appreciated.

Norm

04 Intrigue #11773

Re: Onan 8K QD runs out of fuel

Reply #1 –
Yahoo Message Number: 115407
You might want to check your fuel line for cracks. It's 14 years old. Could be sucking air?

Re: Onan 8K QD runs out of fuel

Reply #2 –
Yahoo Message Number: 115409
The pump could be bad, I lost one.
This is probably the easier fix, the pick up tube could have broken off in the tank.

Re: Onan 8K QD runs out of fuel

Reply #3 –
Yahoo Message Number: 115410
You might take a close look at your fuel lines...mushy, sharp bend, fuel tank vent blocked, loose fitting.
cc5851

Re: Onan 8K QD runs out of fuel

Reply #4 –
Yahoo Message Number: 115412
Interesting. But if the pick-up tube had broken off, wouldn't that mean that the genny would run 'til the tank was emptier, rather than fuller? I think it comes from the bottom of the tank, doesn't it?

Don Hutchins
'08 Allure 470 # 31613
Don Hutchins
'08 Allure 470 #31613
40' w/tag, Cat C-9 & Cat tranny

Re: Onan 8K QD runs out of fuel

Reply #5 –
Yahoo Message Number: 115413
Don, I believe the fuel pickup tube comes down from the top of the tank. I will be looking at that today along with the other suggestions of checking the fuel lines. I agree if the pickup comes from the bottom of the tank then I should not be having the the problem.. I know there is very little clearance between the top of the tank and the floor of the coach so removing the pickup from the top will be very hard to do.

I will post the fix when I find it.
Thanks for the suggestions.
Norm
04 Intrigue #11773

Re: Onan 8K QD runs out of fuel

Reply #6 –
Yahoo Message Number: 115415
Norm,

On my 1995 Magna the fuel line for the generator was on the top front of the tank. Tube drops down to about 6 inches from the bottom of the tank.
Reason I know, had to replace the fuel line. Had cracks in it which caused it to suck air and not fuel, which in turn caused the gen to not run. U might be getting just enough fuel with a full tank? I changed out the whole line, found lots of cracks. Also, might try a air compressor. Disconnect fuel line at gen pump, run 50/60 psi And listen for bubbles in fuel tank or air leak?
Steve
Magna 5220

Re: Onan 8K QD runs out of fuel

Reply #7 –
Yahoo Message Number: 115416
You need to replace the hose from the tank to the generator first and keep your fingers crossed. Then maybe add a conditioner. You may have algae partially blocking the pick up tube. Other wise they are going to drop the tank and thats time consuming. $$$$$ TWInsall 2004 intrigue 11731

Re: Onan 8K QD runs out of fuel

Reply #8 –
Yahoo Message Number: 115417
I found a small leak on the intake hose at the generator connection. I cannot get to the tank connection to replace the hose. I need someone with long arms or I will have to drop the tank at least a couple of inches. I did check the pump to make sure it has enough suction by getting 2 gallons of diesel and putting a clear plastic tube connected to inlet of the generator. I set the can about level with the bottom of the main tank and then raised the middle of the line to a level higher than the top of the tank. The pump lifted the fuel and the genny ran fine. I fixed the leak at the connection and I will not know if that was the problem until I run the main tank level down some. That won't be for a week or two.

Thanks again for all of the suggestions.
Norm

04 Intrigue #11773

Re: Onan 8K QD runs out of fuel

Reply #9 –
Yahoo Message Number: 115418
Just for s and g. When I replaced the fuel line I had to take out the top 2 8D batteries and crawl in to the side of the tank. Found just a hose clamp at the fuel tank end of the line. Took almost 17 feet of hose to replace the whole line.
Steve
1995 Magna

Re: Onan 8K QD runs out of fuel

Reply #10 –
Yahoo Message Number: 115420
Just a reminder along the liens of non solid fuel lines, installed in coaches that were designed to be fed with Old Type II Diesel (Vs ULSD) - ULSD did/does not play well with many of the gaskets and non solids fuel lines installed in that era. They slowly, some faster then others, are eroded by the makeup of ULSD fuels. This causes porosity like pin holes, and thus leakage. If someone with a porosity leaking fuel line only had say generator, or Aqua/Hydro Hot related performance problems - they should consider themselves lucky. Coaches, boats, etc. - have caught on fire due to diesel fuels hitting hot surfaces, such as say exhausts.

We ran new fuel lines (Gates Barricade, but from what I understand, all of the newer fuel lines compounds have been modified to handle ULSD fuels.), to our Onan QD8000, and HydroHot. No signs of problems, but did it as preventative maintenance. (One I did myself, the other I had done when the generator was dropped for other service.).

OP - Best of luck to you on this. Please circle back and let us know what you determine to have been the problem.

Smitty
04 Allure 31017
04 Allure Sold to a nice new owner! Now enjoying a 07 Magna Rembrandt 45' ISX600 #6775
"We're ONDROAD for THEJRNY!" (Toad and Coach license plates, say Hi if you see us!)

Re: Onan 8K QD runs out of fuel

Reply #11 –
Yahoo Message Number: 115423
Thanks Smitty for the information on the fuel line issue with USLD. The fuel line connections are on top of the fuel tank and are very hard to access. I repaired the leaky line found at the generator by splicing in a short piece of line.
I will follow up when I know if that fixed the problem.

Norm
04 Intrigue #11773.

Re: Onan 8K QD runs out of fuel

Reply #12 –
Yahoo Message Number: 115425
That just happened to us It ended up a 36 error code and we were sucking air as a fuel line had an issue All good after it was replaced

Kathy
06 Inspire #51782