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


Reply
 
Thread Tools Display Modes
 
Old 10-15-2021, 03:27 AM   #1
Platinum Member
 
Join Date: Mar 2017
Location: Nebraska
Posts: 131
Default Ongoing Onan 2800 Genset Problem

I am having a very difficult time starting my Onan 2800 genset. It seems to be related to temperatures below 70 degrees. It will start and run fine at first, but only for about 10 seconds. I have to wait at least 30 seconds before trying again, else it will not start at all. After waiting, it will again start, but only for about 5 seconds now. When repeating the process, each attempt runs a little longer, until after about 12 attempts it will finally keep running.

I previously posted about this problem about 18 months ago and replacing the fuel pump was recommended. This was done a year ago last June and a new fuel line and filter was added while the genset was out. We used the camper very little in cooler weather since then, so no problems came forth until this trip. This morning the problem became even more severe, with the genset never running beyond a few seconds, forcing me to give up running it.

Can fuel pumps fail so quickly? Could the fuel pump be replaced with an electric one? Since I think it is temperature related, could it be due to a failing automatic choke? Does it have an automatic choke? Any comments or suggestions? Thanks!
__________________

gksmith is offline   Reply With Quote
Old 10-15-2021, 04:05 AM   #2
Platinum Member
 
Join Date: Dec 2015
Location: Arizona, Tempe
Posts: 1,168
Default

Quote:
Originally Posted by gksmith View Post
Can fuel pumps fail so quickly? Could the fuel pump be replaced with an electric one? Since I think it is temperature related, could it be due to a failing automatic choke? Does it have an automatic choke? Any comments or suggestions? Thanks!
The short answer is yes. Took me three to get one to last. That does not mean that is your problem. I think you can reach in and activate the choke, which is automatic, to help you troubleshoot. You can remove the fuel line after the fuel pump and see if the electric pump is working.

You can also remove the air filter and choke it with your hand over the inlet to see if you can get it to run. It does sound like a fuel problem. If the pump is good then a fuel passage or two is obstructed in the carb. Just guesses.
__________________

hbn7hj is offline   Reply With Quote
Old 10-16-2021, 09:59 PM   #3
Platinum Member
 
Join Date: Mar 2017
Location: Nebraska
Posts: 131
Default

Thanks for you suggestions. I am almost at my wits end, having to remove the genset 3 times in 5 years at over $500 each time. Once to replace the control board (which did resolve a problem), second to only adjust the choke, and thirdly to replace the fuel pump, filter, and fuel line. Since labor is the most expensive component and parts are as relatively inexpensive, I am considering replacing both the carburetor and fuel pump at the next service.
Does this seem reasonable???
gksmith is offline   Reply With Quote
Old 10-16-2021, 10:15 PM   #4
Platinum Member
 
Join Date: Dec 2015
Location: Arizona, Tempe
Posts: 1,168
Default

Dunno, probably, a replacement carb can be had on Ebay for $30 rather than the Cummins charge pushing $300. It would be a better use of your money to be able to drop it yourself.

Let us know what your situation is (driveway, apartment parking) and let’s figure out how to set you up to do it yourself. It ain’t hard once you figure it out and a whole lot cheaper than $500.

If you were in Phoenix you could do it in my driveway.

Replacing the carb and fuel pump does seem like good advice to self.

Is it running now?

I do value a running, installed, generator. For me the next time it comes out an Onan 2800i is going in. Are you in a posiition to do that?
hbn7hj is offline   Reply With Quote
Old 10-16-2021, 10:26 PM   #5
Platinum Member
 
Join Date: Aug 2010
Location: Minnesota
Posts: 10,170
Default

Or you could just bit the even bigger bullet and get a new style Onan fuel injected inverter generator. Smoother, quieter, and hopefully more reliable and actually have all the parts available.
booster is online now   Reply With Quote
Old 10-16-2021, 10:34 PM   #6
Platinum Member
 
Join Date: Dec 2015
Location: Arizona, Tempe
Posts: 1,168
Default

A quick look gets a purchase price of around $3k, in stock, and free shipping. I think someone around here got better than that. It does not appear they are back ordered anymore.

There are install problems to solve like the exhaust system. It is different on the new one and no one has posted about the changes required.
hbn7hj is offline   Reply With Quote
Old 10-17-2021, 03:29 PM   #7
Platinum Member
 
Join Date: Mar 2017
Location: Nebraska
Posts: 131
Default

I have a flat driveway, so that is a plus. But my lack of self confidence towards the job is a big negative. The last two times it was removed (one at Cummins), they commented on how difficult it was to do and both times they called me to make sure I wanted to continue! I believe the unit has to be dropped down.
I have been on the road and the last time I tried to start the genset, the temperature was in the 50s and I gave up trying as the run time would not increase over about 4 seconds. Today the temperature is suppose to get into the mid 70s so I will try again. When I get home, I will see if I can manipulate the choke manually.
I have not compared model numbers, but I think Amazon has carbs for a reasonable price, too. At least nuch less than Cummins $300!
I probably do not want to install a new genset as we are almost ready to make a deposit and make the two year wait for a new Class B, but I sure would like to have a working genset in the meantime!
Thanks!
gksmith is offline   Reply With Quote
Old 10-17-2021, 04:59 PM   #8
Platinum Member
 
Join Date: Mar 2020
Location: NY
Posts: 124
Default

Quote:
Originally Posted by hbn7hj View Post
The next time it comes out an Onan 2800i is going in.
Just out of curiosity, are the newer Onan 2800's drop-in replacements, like for a 20 year old generator in an old Dodge Roadtrek?
RT-NY is offline   Reply With Quote
Old 10-17-2021, 05:06 PM   #9
Platinum Member
 
Join Date: Dec 2015
Location: Arizona, Tempe
Posts: 1,168
Default

There is a thread on here written by a Canadian fellow detailing the removal and replacement of the underhung generator. The instructions are quite good.

The AC power line goes through the floor to the transfer switch. Most of us end up cutting it and put in a junction box on a frame rail after a removal or two. It isn’t too difficult to pull the wire from the transfer switch.

You don’t need a special lift to drop it and everyone that does it seems to develop their own technique. The 12 volt line goes direct to the battery with no fuse so you start by disconnecting it from the battery. You can do it if you want to bad enough.

I have done it in a friends driveway in a remote mountain town.
hbn7hj is offline   Reply With Quote
Old 10-17-2021, 05:12 PM   #10
Platinum Member
 
Join Date: Dec 2015
Location: Arizona, Tempe
Posts: 1,168
Default

Quote:
Originally Posted by RT-NY View Post
Just out of curiosity, are the newer Onan 2800's drop-in replacements, like for a 20 year old generator in an old Dodge Roadtrek?
No, not quite. If yours is in a compartment you need to check the height difference for fit. The exhaust comes out the side rather than the bottom and the AC line may come from a different corner. No one that has done it has written up their experience but it has been done in the underhung installation.
hbn7hj is offline   Reply With Quote
Old 10-18-2021, 07:20 PM   #11
Platinum Member
 
Join Date: Dec 2011
Posts: 1,505
Default

This is my 2 cents working with the best generator guy* in Los Angeles but these options are probably similar to where you are in Nebraska.

Paid $800 to have my 04 Roadtrek 2.8 Onan overhauled & a junction box installed (this is a crucial improvement that makes it very easy to drop & install the Generator - at the time Roadtrekdid not come standard with such a box).

Turned out the reason my unit wouldn't run was a little white plastic piece that gets worn away, about a $1.50 part deep in the generator that necessitated dropping the unit

Next.

Then during the pandemic the Regulator went & my Onan expert was closed - cannabilized a Regulator for $50 off another defunct generator in his yard (saved $250+ over OEM new), & had a Lawnmower Shop do the install, $300 or less including Labour.

My suggestion; find a Lawnmower Repair Facility - the Generator is essentially a Lawnmower Engine & these guys work on them all the time at a fraction of the cost of a Specialist.
__________________
Full Timer in a 2005 Roadtrek Versatile 190/Super Modified & Lifted, Two 220ah Lifeline 6 Volt AGMs in Series, 250 watts Solar, Victron BMV712 Meter & Victron MTTP 100V/30A Solar Controller, Magnum MMS1012 Inverter Charger, Onan 2.8 Generator, Novakool R3800 Fridge & more ...
themexicandoctor is offline   Reply With Quote
Old 10-21-2021, 05:24 PM   #12
Gold Member
 
Join Date: Sep 2017
Location: WA
Posts: 86
Default

If this is in a Chevy Roadtrek have you tried starting the engine first? Pressurizing the fuel tank can help start the generator. Don't know if this helps on Dodges.

Have you tried ether? (Starting fluid.) The Onan in our '01 Roadtrek will never start when not used after 3 or 4 days, even with the engine trick. A good squirt of starting fluid gives the generator a kick in the pants, so to say. It may stall immediately, but after a second squirt it coughs to life, runs rough for a few seconds, and then settles down and runs fine. It will start right up the next day.

For sure something is wrong with our generator, but given the expense of having an Onan dealer work on it, and the fix not enduring long, I don't mind buying one or two cans of ether every year.
rtbill is offline   Reply With Quote
Old 10-21-2021, 08:35 PM   #13
Platinum Member
 
Join Date: Mar 2018
Location: Tinley Park IL
Posts: 175
Default

Often times when it starts and dies it can be low oil. Even a few ounces. Oil gets pumped up, and then causes the low oil safety to kick on and turns off the generator. Also, if you are in a different location make sure the simple adjustable altitude is set correctly. Sometimes we look for the difficult solutions and it may be something as simple as that.
ChicagoTom is offline   Reply With Quote
Old 10-22-2021, 09:31 PM   #14
Silver Member
 
Join Date: Sep 2018
Location: Mendocino County, CA
Posts: 53
Default

For what it's worth
I bought a new Paseo in 2018 with an Onan. The Paseo sits most of the time. When I tried the generator after sitting for probably a year, it would start and immediatly shut off. Same thing as I tried various times over the next few weeks. Attempted to get an Onan rep to come look at it, but living nearly 100 miles from their rep's location, never worked out.

Since the unit was still under warranty, with about 1.8 hours on it, I called an Onan service center and made an appointment. Got to the Center only to discover their only qualified person was out, and no one could look at it. Asked me if I could leave it for a few days. No, since i lived 100 os so miles away and hadn't arranged for a ride home.

Preparing to head home, and a bit annoyed, one of the service folks asked if I had tried SeaFoam? No, never heard of it. He said to try it. Okay, went home aand looked it up on Amazon, read the reviews, and ordered a case of it, along with a spray can of the stuff.

Poured a can into the gas tank and let it sit for a day or two. After sitting for a day or two I gave the Onan's carborator a good shot from the spray can, noticing as I did the choke flapper might have acted a bit sticky.
Tried starting the generator two or three times in quick succession and the little bugger started and kept running! Now I try to remember to start it every two or three months and it never fails to start. I do add a can to the gas tank whenever I fill up.

Maybe the choke was stuck, or this SeaFoaam stuff is that good, but my Onan starting problem went away, so that's my story and I'm sticking with it.

One thing I notice after running it few minutes, the generator starts to "lope", running fast then slow, fast the slow. I can't remember if that "lopeing" stops if I add a load, like the a/c, but I assume that adjusting the idle setting may eliminate that.
Alec
Alec is offline   Reply With Quote
Old 10-23-2021, 01:31 AM   #15
Platinum Member
 
Join Date: Dec 2011
Posts: 1,505
Default

I recently had a glorious Seafoam experience myself with an Italian Scooter & its carb - there is a reason Mechanic's call it a "Tune Up in a Bottle..."

My suggestion to the poster above, run your Generator at least 2 hours per month, or one hour every 2 weeks, after it has started for 5 minutes, put it under load ie; run the AC/heat Pump for the duration.
__________________

__________________
Full Timer in a 2005 Roadtrek Versatile 190/Super Modified & Lifted, Two 220ah Lifeline 6 Volt AGMs in Series, 250 watts Solar, Victron BMV712 Meter & Victron MTTP 100V/30A Solar Controller, Magnum MMS1012 Inverter Charger, Onan 2.8 Generator, Novakool R3800 Fridge & more ...
themexicandoctor is offline   Reply With Quote
Reply

Tags
onan 2800, starting

Thread Tools
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


» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT. The time now is 09:07 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
×