HOME FORUM RULES CONTACT
     
   
   

Go Back   CLASS RACER FORUM > Class Racer Tech > Support Tech


Reply
 
Thread Tools Display Modes
Old 09-24-2013, 11:40 PM   #31
Don Higgins
Junior Member
 
Join Date: Jul 2007
Location: mapleton, IL
Posts: 47
Likes: 0
Liked 0 Times in 0 Posts
Default Re: Generator Questions and Answers, by R&J Control Inc

I have been battling a 10 K Onan generator that will run all day at times then slowly shut down every 30 minutes at night. The code it generates is 36.

I put a new fuel filter, air filter, checked all tubing for plastic bags and changed the oil and filter. The engine is the Isuzu. The only thing I can say that may help is the fuel pump return line stops pulsing when the engine was about to die. When I pushed the return line over to the side to restrict it the engine sprang back to life.

I think the fuel pump isn't pumping or the board isn't telling the pump to continue pumping. I will replace the pump this week but do you have any other ideas? Slate Cummings was having the exact same problem this week but he replaced the pump and it still slowly dies every 30 minutes.
__________________
Don Higgins - Super Comp #360H
Don Higgins is offline   Reply With Quote
Old 09-25-2013, 09:14 AM   #32
Matt Schurman
Sponsor
 
Join Date: Jan 2003
Location: New Jersey
Posts: 42
Likes: 0
Liked 0 Times in 0 Posts
Default Re: Generator Questions and Answers, by R&J Control Inc

Good Morning.

The last two posts require different responses, which will both lead in similar directions. So bear with me, this stuff is work....lol

First, NHRA1285, your code 17 is a fuel pump fault code, which is trigger by the controller unable to sense the electric pump. This is a bypassable fault, which means it can be reset and ignored, but that information is pretty much useless if the machine won't run. When the control doesn't "see" the fuel pump in the circuit, it won't allow the engine to crank, it just drops right into a fault 17, so the fuel pump and wiring needs to be tested.

Your unit is installed without regard for making this type of repair within the confines of a Class A motorcoach. Without seeing the installation I can't say for sure but I'm fairly certain it will have to come out to chase this problem down. It's a big pain and yes, it will probably come out the bottom of the coach. We use a forklift and a great deal of cursing. Give me a call to discuss, I think I can help you more over the phone with some of the details. 800-821-5973
__________________
Matt Schurman
Matt Schurman is offline   Reply With Quote
Old 09-25-2013, 09:23 AM   #33
Matt Schurman
Sponsor
 
Join Date: Jan 2003
Location: New Jersey
Posts: 42
Likes: 0
Liked 0 Times in 0 Posts
Default Re: Generator Questions and Answers, by R&J Control Inc

Don,

Your problem is becoming fairly common for us to see. Replacing the fuel pump is a good place to start, we do some bench testing of the pump to confirm failures but changing it out in the field serves a good purpose. Sometimes it's just a bad fuel pump that goes intermittent.

In some other instances we've seen issues stemming from too much current on the pins of the ECM providing power to the fuel pump. Sometimes the only way to fix it is to replace the ECM AND the pin connection supplying the positive pump signal. That pin can be inspected carefully, if it shows signs of gray/overheat, the problem is identified. We then cut out that wire in the ECM harness and replace it, giving you a nice new connection as well as replacing the ECM, (which gives you a new pin contact)

If you supply me with the model and spec number, I'm certain I can provide you with some diagrams and tech support. 800-821-5973
__________________
Matt Schurman
Matt Schurman is offline   Reply With Quote
Old 11-21-2013, 10:16 PM   #34
a pontiac
Junior Member
 
Join Date: Jan 2011
Posts: 60
Likes: 1
Liked 35 Times in 10 Posts
Default Re: Generator Questions and Answers, by R&J Control Inc

I have a 02 fleeetwood rv onan quiet diesel 7500. The manual says it should have the belt replaced at 1500 hrs. Is this something I can do like other routine maintenance? You guys are providing a great service, thank you.
a pontiac is offline   Reply With Quote
Old 11-22-2013, 03:12 PM   #35
Rich Biebel
VIP Member
 
Rich Biebel's Avatar
 
Join Date: Jun 2007
Location: Northern New Jersey suburbs
Posts: 2,273
Likes: 25
Liked 510 Times in 200 Posts
Default Re: Generator Questions and Answers, by R&J Control Inc

The belt on most of those QD 7500's is the water pump drive belt. It has no adjustment. The sheet metal covers need to be removed and in motorhomes that often means the unit has to come out. Since there is no adjustment.....the water pump pulley must be removed to remove and replace the belt. The fit has to be reasonably tight so the right belt is important. The belts crack and if it is not changed could break and the unit will obviously overheat. I usually change the t-stat and temp sensor at the same time. Deposits build up on the sensor and they can cause poor cold starts and random shutdowns. The sensor signals the controller by way of an ohm reading what the coolant temp is and this controls the glow plug operation....If the unit is cold....the glow plugs are powered before cranking.If it is warm they do not energize.
__________________
Rich Biebel
S/C 1479
Rich Biebel is offline   Reply With Quote
Old 01-12-2014, 07:50 PM   #36
Mark Lewis
Member
 
Join Date: Apr 2006
Posts: 330
Likes: 55
Liked 183 Times in 37 Posts
Default Re: Generator Questions and Answers, by R&J Control Inc

I have a Onan Marquis 5500, model # 5.5BGMFA26105H.
Do not know the hours on it and it runs good .Unit is at least 13yrs old.
I recently had to replace the fuel pump.
The only issue I have is it seems to get lugged down when I turn the AC on, has a 13500 roof air unit on trailer.
Is there anything that needs to be done to the generator part as far as routine maintenance goes? All I have is a 5 gal hot water heater and microwave besides the ac.

Thanks for the help
Mark Lewis
Mark Lewis is offline   Reply With Quote
Old 01-13-2014, 04:30 PM   #37
Rich Biebel
VIP Member
 
Rich Biebel's Avatar
 
Join Date: Jun 2007
Location: Northern New Jersey suburbs
Posts: 2,273
Likes: 25
Liked 510 Times in 200 Posts
Default Re: Generator Questions and Answers, by R&J Control Inc

Mark......Those older Onans run well and should easily run your AC and other items at the same time. The rated output on a 5500 is about 45 amps at 120 volts. An ac unit probably draws no more than 15 amps and a microwave maybe 10, Hot water heater I would guess another 10 tops so you are well within the generators capability.

The older Onans were flathead engines. 1800rpm. They tend to carbon up heavily inside the cylinder heads and intake ports. The rear intake port often is much worse with that carbon buildup. The engine supplies the power to spin the rotor of the generator. The magnetic field created as load increases is the load the engine sees. So if the engine is weak it cannot "carry the load" of the magnetic field in the generator. There is basically nothing in the generator end to service other than the brushes. They are either good or bad and if they are bad you will not have any AC output and the unit will likely not stay running due to loss of AC output.

The first thing to do is make sure the std tune-up items are good and if the machine has a lot of hours on it......a heads off carbon cleaning might be what it needs. Valve lash is also a big factor that causes them to run weak. Exhaust valves get tight, not enough lash and once the engine is hot they run poorly from improper valve seating. lash is .005 Intake and .013 exhaust cold.

I remove the heads......remove the manifolds.....clean the carbon in the heads and ports and the backs of the valves. Adjust the valve lash and reassemble it.......Carb has to be good.....Governor arm and all adjustments set carefully under load for best operation. I use a resistive load bank on all the units I service and repair. Everyone gets tested and adjusted with no load and right up to full rated load. Carbs are very sensitive on mixture and governor arm adjustments.....
__________________
Rich Biebel
S/C 1479

Last edited by Rich Biebel; 01-13-2014 at 06:32 PM.
Rich Biebel is offline   Reply With Quote
Old 02-16-2014, 11:14 PM   #38
5848
Junior Member
 
5848's Avatar
 
Join Date: Dec 2005
Location: nebraska
Posts: 51
Likes: 776
Liked 27 Times in 10 Posts
Default Re: Generator Questions and Answers, by R&J Control Inc

I have the chance to purchase a Onan Emerald 1 Genset 4Kw rv generator and was wondering your thoughts on this model? This would go into our race trailer.
5848 is offline   Reply With Quote
Old 02-17-2014, 06:47 PM   #39
Rich Biebel
VIP Member
 
Rich Biebel's Avatar
 
Join Date: Jun 2007
Location: Northern New Jersey suburbs
Posts: 2,273
Likes: 25
Liked 510 Times in 200 Posts
Default Re: Generator Questions and Answers, by R&J Control Inc

Quote:
Originally Posted by 5848 View Post
I have the chance to purchase a Onan Emerald 1 Genset 4Kw rv generator and was wondering your thoughts on this model? This would go into our race trailer.
They were good units.....but that would be a pretty old unit. They have not made that design for over 10 years. Did it have an hour meter attached to it ? It's always helpful to know the amount of usage on a machine of that vintage. An hour meter is the closest thing to an odometer.

I would not buy one unless it looked to be well cared for and could be tested. It is very easy to run one even if it is not installed in anything.

Add a battery and a gas can and run it and check the output voltage. I run every unit I work on....on a bench and it gets load tested with a resistive load bank to full rated load.....It's a lot of work to install one in a trailer or M-H so it should be confirmed as good before doing an install....
__________________
Rich Biebel
S/C 1479
Rich Biebel is offline   Reply With Quote
Old 02-17-2014, 10:35 PM   #40
5848
Junior Member
 
5848's Avatar
 
Join Date: Dec 2005
Location: nebraska
Posts: 51
Likes: 776
Liked 27 Times in 10 Posts
Default Re: Generator Questions and Answers, by R&J Control Inc

The hour meter has 232 hrs on it and the unit does look to be in good condition. What is the noise decibel on one of these units? There are asking $500 for the unit.
Thanks
5848 is offline   Reply With Quote
Reply


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

Forum Jump


All times are GMT -4. The time now is 04:54 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright © Class Racer.com. All Rights Reserved. Designated trademarks and brands are the property of their respective owners.