Free 7 Day Trial RV GPS App RV Trip Planner Campground Reviews RV Maintenance Free 7 Day Trial ×
 


Reply
 
Thread Tools Search this Thread Display Modes
 
Old 02-11-2021, 01:43 PM   #1
Rivet Master
 
92landyacht's Avatar
 
1992 36' Land Yacht
Grayson , Georgia
Join Date: Nov 2011
Posts: 1,417
Generator fuel problem

I was running the generator as normal monthly test and after about 15 minutes it just quit. Upon further inspection I found that I had no fuel pressure. I replaced the pump a few years ago and it's ran fine since. I checked the input line to the pump and found no fuel coming out. If I suck on the line I can get gas to come out and will continue to come out. I drained about a gallon before I stopped it by reconnecting the fuel line. After it again started and ran for about 15 minutes and again quit with no fuel pressure. Disconnected the fuel input line and again it had no gas coming out.

I've ordered another fuel pump as it good to have a spare anyways. Is there a way to verify that the fuel line going from the tank to the generator is OK and not leaking and sucking air?

For what it's worth, it's a 1992 P30 36' Landyacht with tag axle and the fuel tank has never been dropped.
92landyacht is offline   Reply With Quote
Old 02-11-2021, 02:08 PM   #2
Rivet Master
 
Magnet18's Avatar
 
Churubusco , Indiana
Join Date: Nov 2017
Posts: 1,966
My 83 is 9 years older, but when I dropped the tank the original fuel lines literally crumbled to pieces. The 1/4" rubber hose should be pretty cheap. If you have access to the top of the tank you won't need to drop it
Attached Thumbnails
Click image for larger version

Name:	PXL_20210106_023005467.jpg
Views:	10
Size:	313.8 KB
ID:	388491  
Magnet18 is offline   Reply With Quote
Old 02-11-2021, 03:54 PM   #3
Rivet Master
 
2018 25' International
Slidell , Louisiana
Join Date: Sep 2017
Posts: 3,477
Given that you were able to siphon gas out of the line confirms there is no leak as it would not hold the vacuum. Get a new pump and make some electricity.
__________________
Brian
BayouBiker is offline   Reply With Quote
Old 02-12-2021, 08:39 AM   #4
Rivet Master
 
92landyacht's Avatar
 
1992 36' Land Yacht
Grayson , Georgia
Join Date: Nov 2011
Posts: 1,417
While I'm replacing the fuel pump, I was thinking about moving it to the rear near the tank and making it more accessible so I don't have to drop the genset if it goes out again. It may also make it easier for the pump to prime and push fuel to the generator. Any thoughts on this?
92landyacht is offline   Reply With Quote
Old 02-12-2021, 08:47 AM   #5
Rivet Master
 
Magnet18's Avatar
 
Churubusco , Indiana
Join Date: Nov 2017
Posts: 1,966
Quote:
Originally Posted by 92landyacht View Post
While I'm replacing the fuel pump, I was thinking about moving it to the rear near the tank and making it more accessible so I don't have to drop the genset if it goes out again. It may also make it easier for the pump to prime and push fuel to the generator. Any thoughts on this?
Pumps push fuel much much better than they pull fuel. Sounds like a good idea to me.

I didn't realize your generator pump was electric. Can you disconnect the pump output and see if it still cuts off after a few minutes without the generator running at all? Could be an easy way to isolate it to the pump.
Magnet18 is offline   Reply With Quote
Old 02-12-2021, 09:24 AM   #6
Rivet Master
 
92landyacht's Avatar
 
1992 36' Land Yacht
Grayson , Georgia
Join Date: Nov 2011
Posts: 1,417
Quote:
Originally Posted by Magnet18 View Post
Pumps push fuel much much better than they pull fuel. Sounds like a good idea to me.

I didn't realize your generator pump was electric. Can you disconnect the pump output and see if it still cuts off after a few minutes without the generator running at all? Could be an easy way to isolate it to the pump.
I was thinking about doing that but not sure how to simulate the small amount of fuel flow and back pressure that the pump would normally see when connected to the generator. The pump seems to be running but I'm not getting a lot of fuel, if any, after a few minutes from the feed line to the carb.

One things for sure, If I move the pump to the rear and pressurize the line going to the generator, I'm bound to find if there are any leaks between the pump and the genset. Something that I would check for very carefully.

If I do have to drop the tank to replace any rotted fuel lines, anyone have any suggestions? I was planning on using a motorcycle jack to let the tank down and put it back up. I used one to remove the genset the last time. The one I have is like this one from Harbor Freight:

92landyacht is offline   Reply With Quote
Old 02-12-2021, 09:48 AM   #7
Rivet Master
 
2018 25' International
Slidell , Louisiana
Join Date: Sep 2017
Posts: 3,477
positive displacement pumps can pull a fair amount of vacuum so moving it won't make that much difference. Convenience is a good reason to relocate it, but if you have to drop the tank it sort of defeats that. I would find an easy spot to locate the pump, cut the fuel line there and then use air to pressure test the line forward. If it fails, then I would replace it and consider replacing the suction side as well.
__________________
Brian
BayouBiker is offline   Reply With Quote
Old 02-12-2021, 10:07 AM   #8
Rivet Master
 
92landyacht's Avatar
 
1992 36' Land Yacht
Grayson , Georgia
Join Date: Nov 2011
Posts: 1,417
Quote:
Originally Posted by BayouBiker View Post
positive displacement pumps can pull a fair amount of vacuum so moving it won't make that much difference. Convenience is a good reason to relocate it, but if you have to drop the tank it sort of defeats that. I would find an easy spot to locate the pump, cut the fuel line there and then use air to pressure test the line forward. If it fails, then I would replace it and consider replacing the suction side as well.
I still need to get under the MH to take a better look at how the tank is arranged and if the lines are exposed, but that will have to wait for another day since it's raining and I'm not in that big of a hurry.

Replacement pump should arrive today. Just for reference sake, the replacement pump for my Onan Marquis 7000 is a Carter P4070. Same pump that Onan used but MUCH less expensive since it's not marked Onan.

I guess the good news is that I don't project needing the generator until October, so I do have some time. I have three trips planned before then but all of those will have good electrical at the camp site.
92landyacht is offline   Reply With Quote
Old 02-12-2021, 10:13 AM   #9
Rivet Master
 
Magnet18's Avatar
 
Churubusco , Indiana
Join Date: Nov 2017
Posts: 1,966
I used a transmission jack pretty easily to aid in removal. If you want more area you can easily bolt custom pieces of wood to it. I'd think a motorcycle jack would work really well too. If you can use an electric fuel pump to pump the fuel out it'll work a lot better than siphoning.

For reinstallation the jack would have worked but I just pushed it up by hand. Jack would have been easier but I was too lazy to go get it from the other end of the shop
__________________
1983 Airstream 310 Class A Motorhome
-Rob
Magnet18 is offline   Reply With Quote
Old 02-12-2021, 10:45 AM   #10
Airstream Driver
 
PeterH-350LE's Avatar

 
1994 30' Excella
1992 35' Airstream 350
Austin , Texas
Join Date: Feb 2002
Posts: 4,823
Images: 49
Just run a fuel line in a gas canister and see if it runs more than 15 minutes. Dropping the tank is easy after you empty it. Even when empty the 80 gal tanks are very heavy. I use a floor jack with a modified platform to distribute the weight. Biggest issue is that you have to drive up on ramps for clearance
PeterH-350LE is offline   Reply With Quote
Old 02-12-2021, 01:20 PM   #11
Rivet Master
 
92landyacht's Avatar
 
1992 36' Land Yacht
Grayson , Georgia
Join Date: Nov 2011
Posts: 1,417
Quote:
Originally Posted by PeterH-350LE View Post
Just run a fuel line in a gas canister and see if it runs more than 15 minutes. Dropping the tank is easy after you empty it. Even when empty the 80 gal tanks are very heavy. I use a floor jack with a modified platform to distribute the weight. Biggest issue is that you have to drive up on ramps for clearance
I'm betting that I can get to the top of the tank without having to put the MH up on ramps. I can get the rear end pretty high using the leveling jacks and the driveway does slope down toward the rear. Just not looking forward to dropping the tank.

What do you guys think? If I do drop the tank I'm thinking of doing the fuel pump and sending unit along with all the rubber lines. It's the original fuel pump and I know that the gas was old when I first bought it since it sat for at least two years without being started by the previous owner. It's run fine for as long as I've owned it (8 years) but just thinking that this will be the first and ONLY time I want to drop the tank.

Edit:
Based on what I've seen so far I'm thinking that I have a small air leak on the generator line that sucks air in. While the generator is emptying the line, the line is filling with air. When the air hits the pump it no long can pull enough suction to clear the air, the fuel pressure begins to drop and the genset cuts off. I can disconnect the line going into the pump and no gas comes out. If I suck on the line I can overcome the small air leak and pull enough vacuum to begin flow again. If this is the case, than I may end up having to drop the tank to get to the rubber hose at the tank going to the generator. Haven't looked at it yet but I'm betting that the hose is not accessible from the outside with the tank still mounted.

Thanks for the encouragement Peter. I'm going to need it.
92landyacht is offline   Reply With Quote
Old 02-12-2021, 02:02 PM   #12
Rivet Master
 
2018 25' International
Slidell , Louisiana
Join Date: Sep 2017
Posts: 3,477
I don't have any guidance of dropping the tank and doing fuel line replacement.

If you can pull a vacuum and get gas, a pump in good working order can too. even a small air leak would have the thing leaking gas when the tank is full unless it happens to be higher than the top of the tank. Your symptoms are consistent with a weak pump but there is insufficient evidence of an air leak in my mind at this time. I would put a small bit of compressed air into the works and see if any gas comes out....
__________________
Brian
BayouBiker is offline   Reply With Quote
Old 02-12-2021, 02:51 PM   #13
Rivet Master
 
92landyacht's Avatar
 
1992 36' Land Yacht
Grayson , Georgia
Join Date: Nov 2011
Posts: 1,417
Well, the new pump arrived today. My first course of action will be to temporarily connect the new pump to the fuel inlet and connect the outlet to the carb. After that I'll see if it will keep running. If not, then I know I have a fuel line issue since I've checked and I do have power to the pump when I loose fuel pressure. If the genny runs well, I'll locate the new pump to a more accessible location for a permanent mounting and call it a day.
92landyacht is offline   Reply With Quote
Old 02-12-2021, 03:56 PM   #14
Airstream Driver
 
PeterH-350LE's Avatar

 
1994 30' Excella
1992 35' Airstream 350
Austin , Texas
Join Date: Feb 2002
Posts: 4,823
Images: 49
Quote:
Originally Posted by 92landyacht View Post
I'm betting that I can get to the top of the tank without having to put the MH up on ramps. I can get the rear end pretty high using the leveling jacks and the driveway does slope down toward the rear. Just not looking forward to dropping the tank.

What do you guys think? If I do drop the tank I'm thinking of doing the fuel pump and sending unit along with all the rubber lines. It's the original fuel pump and I know that the gas was old when I first bought it since it sat for at least two years without being started by the previous owner. It's run fine for as long as I've owned it (8 years) but just thinking that this will be the first and ONLY time I want to drop the tank.

Edit:
Based on what I've seen so far I'm thinking that I have a small air leak on the generator line that sucks air in. While the generator is emptying the line, the line is filling with air. When the air hits the pump it no long can pull enough suction to clear the air, the fuel pressure begins to drop and the genset cuts off. I can disconnect the line going into the pump and no gas comes out. If I suck on the line I can overcome the small air leak and pull enough vacuum to begin flow again. If this is the case, than I may end up having to drop the tank to get to the rubber hose at the tank going to the generator. Haven't looked at it yet but I'm betting that the hose is not accessible from the outside with the tank still mounted.....



Sorry, I just do not agree working under 16k + pounds using the leveling jacks nor counting on the airbags to stay inflated.
Building ramps is the only safe way for us DIYers. Its cheap and easy to do and you will use them again. And yes, I own 4, you can see the 2 different types and yes they have stops at the end, so you dont drop off.

Even if you would manage to reach the generator connection, what if you discover other issues and now have an empty tank half way down. The filler tube most likely goes through the frame and the tank needs to be tilted to get it in and out. Besides, your tank is probably real rusty inside and the filter sock 2 miles away from being totally clogged up.

Dont be as stupid as I was, when I dropped the tank the first time and didn't bother to get it properly cleaned. I just went through the entire job again, because of that.
Attached Thumbnails
Click image for larger version

Name:	gasTank-axlefloat.jpg
Views:	21
Size:	211.9 KB
ID:	388594   Click image for larger version

Name:	ramp.jpg
Views:	13
Size:	304.9 KB
ID:	388595  

__________________
1994 30' Excella Front Kitchen Trailer
1990 25' Excella Travel trailer
1992 350LE Classic Touring Coach
AIR #13
PeterH-350LE is offline   Reply With Quote
Old 02-13-2021, 06:27 AM   #15
Rivet Master
 
92landyacht's Avatar
 
1992 36' Land Yacht
Grayson , Georgia
Join Date: Nov 2011
Posts: 1,417
Quote:
Originally Posted by PeterH-350LE View Post
Sorry, I just do not agree working under 16k + pounds using the leveling jacks nor counting on the airbags to stay inflated.
Building ramps is the only safe way for us DIYers. Its cheap and easy to do and you will use them again. And yes, I own 4, you can see the 2 different types and yes they have stops at the end, so you dont drop off.

Even if you would manage to reach the generator connection, what if you discover other issues and now have an empty tank half way down. The filler tube most likely goes through the frame and the tank needs to be tilted to get it in and out. Besides, your tank is probably real rusty inside and the filter sock 2 miles away from being totally clogged up.

Dont be as stupid as I was, when I dropped the tank the first time and didn't bother to get it properly cleaned. I just went through the entire job again, because of that.
Peter, give me a little credit for not being, as you said, stupid as you were the first time.

First off, no airbags except on the TAG axle and they're not used when lifting the rear end. The leveling jacks would be used to get the rear end up higher. I always use a pair of 12 ton (24,000# each) big red jack stands on the frame to back them up and wheel chocks to make sure things don't roll. The drive way slopes down from front to back to make it even easier. With the leveling jacks I can get the rear end 18" higher and the jack stands will wedge in there and provide good security. It's not like I've never worked under the MH before. I also have a pair of 20 ton hydraulic jacks to lift things a little higher if need be. There are many ways to slice a cake.

As for cleaning out the tank, it's all in the plan. One of the reasons for this post is to think things through before I start.
92landyacht is offline   Reply With Quote
Old 02-13-2021, 06:36 AM   #16
Airstream Driver
 
PeterH-350LE's Avatar

 
1994 30' Excella
1992 35' Airstream 350
Austin , Texas
Join Date: Feb 2002
Posts: 4,823
Images: 49
Quote:
Originally Posted by 92landyacht View Post
Peter, give me a little credit for not being, as you said, stupid as you were the first time.

First off, no airbags except on the TAG axle and they're not used when lifting the rear end. The leveling jacks would be used to get the rear end up higher. I always use a pair of 12 ton jack stands on the frame to back them up and wheel chocks to make sure things don't roll. The drive way slopes down from front to back to make it even easier. With the leveling jacks I can get the rear end 18" higher and the jack stands will wedge in there and provide good security. It's not like I've never worked under the MH before. I also have a pair of 20 ton hydraulic jacks to lift things a little higher if need be. There are many ways to slice a cake.

As for cleaning out the tank, it's all in the plan. One of the reasons for this post is to think things through before I start.

Didn't mean to offend you just was responding to your post about using leveling jacks. You did not mention using 20 ton jacks...

Quote:
Originally Posted by 92landyacht View Post
I'm betting that I can get to the top of the tank without having to put the MH up on ramps. I can get the rear end pretty high using the leveling jacks and the driveway does slope down toward the rear....
__________________
1994 30' Excella Front Kitchen Trailer
1990 25' Excella Travel trailer
1992 350LE Classic Touring Coach
AIR #13
PeterH-350LE is offline   Reply With Quote
Old 02-13-2021, 07:39 AM   #17
Rivet Master
 
92landyacht's Avatar
 
1992 36' Land Yacht
Grayson , Georgia
Join Date: Nov 2011
Posts: 1,417
Quote:
Originally Posted by PeterH-350LE View Post
Didn't mean to offend you just was responding to your post about using leveling jacks. You did not mention using 20 ton jacks...
No offense taken.

Actually the jack stands are 12 Ton but you're right I didn't mention them in the original post. I always carry a pair of 20 ton hydraulic jacks, a pair of 12 ton jack stands and four 4" high steel wheel chucks in the large storage bin road side. Using the leveling jacks only to lift but never as the only means of support. Found that my hydraulic leveling jacks can lift any side of the MH up enough to lift tires off the ground on that side if I only choose one side manually.

On one stupid move on my part, I accidentally lifted the rear end so high that all six rear wheels (main and TAGs) were off the ground and the MH started to roll forward since I had no parking brake because of no wheel contact and I forgot to put the wheel chocks under the front tires. I'm not infallible but have learned to keep an order of things since then. Chocks first before anything.
92landyacht is offline   Reply With Quote
Old 02-13-2021, 07:44 AM   #18
Rivet Master
 
AldeanFan's Avatar
 
1977 23' Safari
Niagara on the Lake , Ontario
Join Date: Aug 2011
Posts: 878
Images: 3
You may have a piece of debris in the tank that occasionally blocks the inlet.

I worked in a shop with a guy who was generally disliked by all. One day his car started acting like your generator, it would run for 10-15 min and then no fuel pressure. If he let it sit a few minutes it would restart and run again for 10-15min.

Someone had dropped a condom in his gas tank and it would get sucked on to the fuel inlet. When the engine shut off the condom would float away until the pump started sucking again.
__________________
1977 Safari Land Yacht
2005 Toyota Tundra SR5
2010 Ford Flex Ecoboost
AldeanFan is offline   Reply With Quote
Old 02-13-2021, 09:12 AM   #19
Rivet Master
 
1960 22' Safari
in the wilderness , The great Mojave Desert
Join Date: Jun 2006
Posts: 4,068
While you are replacing the fuel pump. Also replace the fuel line.

They age out and do frustrating things like delaminate and plug itself up.
__________________
I'd rather be boon docking in the desert.

WBCCI 3344 FCU
AIR# 13896
CA 4

Yes, we have courtesy parking for you. About an hour North of Los Angeles.
Goin camping is offline   Reply With Quote
Old 02-13-2021, 10:23 AM   #20
Rivet Master
 
92landyacht's Avatar
 
1992 36' Land Yacht
Grayson , Georgia
Join Date: Nov 2011
Posts: 1,417
So far the plan is to first determine if the problem is local to the generator. Fuel pump is the first order to determine if it's the cause or not. If not, then an inspection of the fuel line going to the tank is in order. Any exposed rubber will be replace along the way. If still having problems then dropping the tank will be the next step. IF I have to drop the tank, then the following will be done:

Replace all rubber lines including fuel supply, fuel return, filler and vents..
Replace engine fuel pump and sock.
Replace fuel gauge sensor.
Inspect and clean tank.

Not currently having any issues with the MH engine or gages but I figure, once the tank is down , it's a good time to replace all that can go bad.

If I get to the point where the tank needs to come down I'll start a new "Drop Tank" thread as that has a lot more detail that needs to be discussed. I'll try to post pictures. Will need to find part numbers for things like the fuel pump and fuel level sensor. Pretty sure the sensor is a 90 ohm unit but I wont know what size until I pull the original one out. P30 fuel pumps for for TBI should be pretty common. Will probably reuse the fuel tree. Not sure if the generator dip tube is integral to the fuel pump tree or a separate inlet to the tank. Not a lot of threads on the 1992 Land Yacht specifically and AS is so good at changes within the same year let alone between years.
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
Low Fuel Warning light ON when Fuel Tank is Full, Not Empty??? Michael_Wild Mechanics Corner - Engines, Transmission & More... 1 07-06-2018 11:26 AM
Fuel Line & Fuel Tank crazeevw Mechanics Corner - Engines, Transmission & More... 4 12-02-2011 07:38 PM
Gasoline Can For Generator Fuel PARKS1963 Generators & Solar Power 9 08-12-2006 08:14 PM
Kohler generator fuel filter ViewRVs Mechanics Corner - Engines, Transmission & More... 3 08-23-2003 06:17 AM
Electric fuel pump and fuel line routing cooperhawk Mechanics Corner - Engines, Transmission & More... 7 02-06-2003 10:16 AM


Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by the Airstream, Inc. or any of its affiliates. Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.



All times are GMT -6. The time now is 07:34 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.