Reply
 
Thread Tools Search this Thread Display Modes
 
Old 07-09-2014, 04:54 PM   #1
Rivet Master
 
92landyacht's Avatar
 
1992 36' Land Yacht
Grayson , Georgia
Join Date: Nov 2011
Posts: 772
Arghh!! Generator shutting off

Just got back from a 4th of July trip and everything went well except for the generator. Some times it runs for a couple hours and sometimes it will only run for 10 minutes. Every time it sputters and quits. Checked the oil level and that's OK. Sounds like it's running out of fuel. The Genset is a Onan NHM Marquis 7KW unit. Guess I've got some troubleshooting to do.
__________________

__________________
92landyacht is offline   Reply With Quote
Old 07-09-2014, 11:55 PM   #2
Registered User
 
1996 32' Cutter Bus
Petaluma , California
Join Date: Jul 2011
Posts: 112
Images: 34
Fuel filter or low fuel level? Mine is surely different (Powertech/Kubota 7000W diesel running off the 90 gal main fuel tank), but it won't work without at least 1/4 tank of fuel in the tank. I also went through about 4 fuel filters when I got my motorhome 3 years ago to clear all the junk out of the lines. It kept stalling on our first trip until I went through at least 3 fuel filters. I also changed the air filter, oil & oil filter later. It runs great now and we do a lot of camping in county, state & national parks w/o hookups and we rely on our genset a lot.


Sent from my iPhone using Airstream Forums
__________________

__________________
AdamB is offline   Reply With Quote
Old 07-10-2014, 01:48 AM   #3
Rivet Master
 
J. Morgan's Avatar

 
1972 31' Sovereign
1975 31' Excella 500
Currently Looking...
Benton , Arkansas
Join Date: Mar 2013
Posts: 5,046
Images: 11
Maybe getting hot and/or vapor lock?

Gas ain't what it was, with fuel injection becoming the rule, gasoline boiling temperature has dropped, so I have read anyway.

(Since gas constantly recirculates with fuel injection, it is not sitting in one place to get hot so the boiling point is not as critical as it used to be)


Sent from my iPhone using Airstream Forums
__________________
The fact that I am opinionated does not presuppose that I am wrong......

J. Morgan is offline   Reply With Quote
Old 07-10-2014, 08:32 AM   #4
Rivet Master
 
92landyacht's Avatar
 
1992 36' Land Yacht
Grayson , Georgia
Join Date: Nov 2011
Posts: 772
Quote:
Originally Posted by AdamB View Post
Fuel filter or low fuel level? Mine is surely different (Powertech/Kubota 7000W diesel running off the 90 gal main fuel tank), but it won't work without at least 1/4 tank of fuel in the tank. I also went through about 4 fuel filters when I got my motorhome 3 years ago to clear all the junk out of the lines. It kept stalling on our first trip until I went through at least 3 fuel filters. I also changed the air filter, oil & oil filter later. It runs great now and we do a lot of camping in county, state & national parks w/o hookups and we rely on our genset a lot.


Sent from my iPhone using Airstream Forums
Tank is over 3/4 full so I don't think that it's the problem. I was able to pump a quart of fuel out into a clear container and found no debris in the fuel. Fuel filter is not obstructed.

Today I added a fuel gauge after the fuel filter. I ran it until it quit (about 1.5 hours). I tried to restart it but it would not build any fuel pressure. I disconnected the fuel line and could see only a dribble of fuel when cranking. I sucked on the fuel line while cranking and found no obstruction to fuel flow. Conclusion at this point is that the fuel pump is going out. I ordered a Carter P4070 fuel pump. The OEM pump sells for over $230 and is made by Carter. Same shape and the same output pressure (4-6psi). I'll update once the pump arrives. Not looking forward to installing it though.
__________________
92landyacht is offline   Reply With Quote
Old 07-10-2014, 10:15 AM   #5
Rivet Master
 
bkahler's Avatar

 
1974 20' Argosy 20
Richmond , Kentucky
Join Date: Jan 2003
Posts: 6,356
Another possibility is the suction line (from fuel pump to tank) has cracks in it. Your Land Yacht will cause all sorts of running and starting problems for the generator.

Worth checking into.

Brad
__________________
Air forums # 1674
1974 20' Argosy Motor Home
1974 31' Excella trailer (parting out, as of 4/1/2015 I have wheels, brake drums, windows & holding tanks left to sell)
bkahler is offline   Reply With Quote
Old 07-11-2014, 03:35 PM   #6
Rivet Master
 
92landyacht's Avatar
 
1992 36' Land Yacht
Grayson , Georgia
Join Date: Nov 2011
Posts: 772
Quote:
Originally Posted by bkahler View Post
Another possibility is the suction line (from fuel pump to tank) has cracks in it. Your Land Yacht will cause all sorts of running and starting problems for the generator.

Worth checking into.

Brad
Good point Brad. I'm actually hoping that it's the pump since tracking down a leak in the fuel line could become even more problematic.

I'm thinking the fuel pump will do it since the pump couldn't pull any fuel but I was easily able to pull fuel by simply sucking on the fuel line. It seemed like the pump had no prime capability. The fuel was clearly right there at the pump, since it took nothing to get fuel to flow with a light vacuum on the line, but the pump still couldn't push any volume or build pressure. Almost like the pump was stalled. I'll let you know since I just got notice that the pump arrived at the house.

Probably going to bypass the current pump and let the new pump pull fuel from the original line to test it. That will tell me if the original pump is bad before I go ahead and attempt to yank the old one out.
__________________
92landyacht is offline   Reply With Quote
Old 07-11-2014, 05:35 PM   #7
2 Rivet Member
 
2017 25' International
Joliet , Illinois
Join Date: Nov 2013
Posts: 78
Also check the vent in the cap. If it is clogged up it will cause a vacuum in the tank and not let the fuel flow. This happened to me once on my riding mower. After I changed the filter, plug and cleaned the carb twice I finally figured it out.

Try running it with the cap loose to see if it still dies.
__________________
bel73 is offline   Reply With Quote
Old 07-11-2014, 08:17 PM   #8
Rivet Master
 
92landyacht's Avatar
 
1992 36' Land Yacht
Grayson , Georgia
Join Date: Nov 2011
Posts: 772
I would think that the engine would have issues then as well. The 454 engine has no issues with running down the road for hours. It draws from the same tank as the genset and pull a ton more fuel/hour.

Replacement fuel pump arrived today. Carter P4070. Looks identical to the OEM Onan pump and has the same pressure rating at 4-6psi. Once I remove the original pump I'll be able to compare item to item. Price difference alone is worth the experimentation. $230 v/s $64 delivered.
__________________
92landyacht is offline   Reply With Quote
Old 07-11-2014, 10:05 PM   #9
4 Rivet Member
 
2017 26' Flying Cloud
Missouri Valley , Iowa
Join Date: Sep 2008
Posts: 338
This is a simple suggestion that may or may not work. Get some Sea Foam gas treatment and put in the gas tank. You may have a jet or small passage that is partially gummed up on the genny carb. This additive works for us on small engines on the farm whether its seed tenders, lawn mowers or ATVs with Honda power, Briggs & Stratton or Yamaha power. I usually end up with it mixed stronger than recommended, but have no problems. I think its a petroleum product anyhow. It'd be an easy try.
Dan
__________________
Farmer Dan is offline   Reply With Quote
Old 07-11-2014, 10:07 PM   #10
3 Rivet Member
 
hissilver's Avatar
 
2018 25' International
Van Wert , Ohio
Join Date: Dec 2011
Posts: 129
One other source for your problem may be a fleck of carbon has attached itself to the spark plug and is not allowing the spark to fire and ignite the pressurized fuel...just a thought
__________________
hissilver is offline   Reply With Quote
Old 07-12-2014, 07:36 AM   #11
Rivet Master
 
92landyacht's Avatar
 
1992 36' Land Yacht
Grayson , Georgia
Join Date: Nov 2011
Posts: 772
Guys, thanks for the input. I've confirmed that, when the problem is occurring, no gas comes out the fuel line when the gen is cranking. After sitting for a while it will pump gas but not for more then a couple hours. Sometimes for a little as 10 minutes. If I feed gas to the carb it starts and runs fine. I figure I'll be able to try to bypass the pump on Weds if weather permits. That will tell me if it's a pump or feed line issue. It's not a gummed up carb problem for sure. Whenever I put gas in the MH I add the appropriate amount of STA-BIL fuel stabilizer.
__________________
92landyacht is offline   Reply With Quote
Old 07-12-2014, 08:11 AM   #12
Rivet Master
 
bkahler's Avatar

 
1974 20' Argosy 20
Richmond , Kentucky
Join Date: Jan 2003
Posts: 6,356
Quote:
Originally Posted by 92landyacht View Post
I would think that the engine would have issues then as well. The 454 engine has no issues with running down the road for hours. It draws from the same tank as the genset and pull a ton more fuel/hour.
One thing to keep in mind, the genset has a different tap into the fuel tank than the 454 engine tap. The genset tap doesn't stick down into the tank as far which means you can't inadvertently suck the tank dry while camping in the middle of nowhere

Quote:
Replacement fuel pump arrived today. Carter P4070. Looks identical to the OEM Onan pump and has the same pressure rating at 4-6psi. Once I remove the original pump I'll be able to compare item to item. Price difference alone is worth the experimentation. $230 v/s $64 delivered.
That's good to know. Where did you order the pump from?

I've attached a couple of pictures of how I did the suction line plumbing on the Kohler in the 310 I used to own.

Click image for larger version

Name:	84-310-kohler-genset-fuel-piping-1.jpg
Views:	304
Size:	263.5 KB
ID:	216189Click image for larger version

Name:	84-310-kohler-genset-fuel-piping-2.jpg
Views:	265
Size:	258.3 KB
ID:	216190

I bought two 1/4" plastic shutoff valves like those used on lawn mowers, etc and also a 1/4" plastic Tee. One shutoff valve goes in the suction line to the coach fuel tank. The other shutoff valve is on the other side of the Tee and I attached about a 5' or 6' long piece of hose to the other Tee that I use to stick into a gas can for testing purposes or if I just want to run the genset for a while without pulling fuel from the main tank.

You have to keep one of the valves closed all the time or the pump won't be able to generate any suction. This arrangement has come in handy several times when I had to troubleshoot problems with the starting/running of the Kohler genset.

Simple and cheap to do and it seemed like a worth while modification.

Brad
__________________
Air forums # 1674
1974 20' Argosy Motor Home
1974 31' Excella trailer (parting out, as of 4/1/2015 I have wheels, brake drums, windows & holding tanks left to sell)
bkahler is offline   Reply With Quote
Old 07-12-2014, 08:20 AM   #13
Rivet Master
 
bkahler's Avatar

 
1974 20' Argosy 20
Richmond , Kentucky
Join Date: Jan 2003
Posts: 6,356
Quote:
Originally Posted by 92landyacht View Post
Whenever I put gas in the MH I add the appropriate amount of STA-BIL fuel stabilizer.
That's something I should be doing as well. Just need to remember to do it
__________________
Air forums # 1674
1974 20' Argosy Motor Home
1974 31' Excella trailer (parting out, as of 4/1/2015 I have wheels, brake drums, windows & holding tanks left to sell)
bkahler is offline   Reply With Quote
Old 07-12-2014, 12:05 PM   #14
Rivet Master
 
92landyacht's Avatar
 
1992 36' Land Yacht
Grayson , Georgia
Join Date: Nov 2011
Posts: 772
Ya, I keep a quart of STA-BIL in one of the lower compartments near the fuel inlet. I figure about how much I'm going to need to fill or put in and dump one Oz per 5 gallons in before I fill. Haven't had a gas related problem for years. Even after sitting for months.
__________________

__________________
92landyacht is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Solar or generator or and generator? badkat Full-Timing 15 11-17-2014 10:59 PM
Door Not Shutting... doglickfarms Doors & Locks 1 04-25-2008 02:02 PM
Arghh...new leaks in Bambi II yukionna Leaks - Weatherstrips, Gaskets, Caulks & Sealants 1 04-15-2007 05:29 PM
Generator Cutting Off swebster Mechanics Corner - Engines, Transmission & More... 17 10-27-2005 07:17 PM
Generator cuts off ALANSD Airstream Motorhome Forums 7 08-03-2003 09:36 AM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 08:35 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.