Onan 4000 generator won't start

[jabrabu]

The Onan 4000 generator in my 2018 Chateau cranks but will not start. It's only 9 months old and has always started easily before.


When I push the stop button to prime it, I hear a sound so I assume the fuel pump is working. I also smell gas so I assume it's getting fuel. I took out the spark plug and saw it sparking when I cranked the generator. However, I had it at a dealership and they said it was not getting spark. They said it needed a new coil and control board and would cost 6 hours labor ($870) plus parts to fix it.


So, a couple of questions:
1. Any advice on how to further troubleshoot this problem?


2. The generator is still within the warranty period, so it should be covered by the Cummins warranty. Has anyone dealt with Cummins to get warranty repair done on a generator?


Thanks,
Brad

[Bob Denman]

Question: how old is the fuel in your tank?
Could you just have some bad gas?
If you've got spark and fuel: "timing & compression" are the only two other variables...

If they're saying that it's not getting spark; and you SAW it: be very careful about this shop!

http://www.thorforums.com/forums/att...1&d=1530278746

[The Gritz Carlton]

Cummins has always been spot on with all that I've read from others. They should authorize CW a diagnosis fee as well as cover the repairs. My question is whether CW is qualified to make legit repairs. Disgusting that they're not even trying to work with Cummins on this. Is there a Cummins dealer or authorized repair center near you? Many shop techs today now work on a commission structure based on repair cost. Warranty work pays minimum fees to them. So often, they try to flip the repair over to a "customer pay" repair. A cheap fix on a gas motor is to always start with replacing the plugs...regardless. The smell of gas is an indication it's getting flooded.

[jabrabu]

Originally Posted by Bob Denman

Question: how old is the fuel in your tank?
Could you just have some bad gas?
If you've got spark and fuel: "timing & compression" are the only two other variables...

If they're saying that it's not getting spark; and you SAW it: be very careful about this shop!

Yeah, that's why I didn't agree to pay them 6 hours labor plus parts to fix it. Also, it should be covered as a warranty repair, but I'm not sure if I should contact Thor or Cummins for that.


The gas is fresh. We use the RV a lot, and we were using the RV and the generator earlier this month.

[The Gritz Carlton]

Shortest distance is to contact Cummins. Warranty should be on file with them or you may need to furnish proof of purchase. They will advise you where to take it.

[halfprice]

Have you checked the oil level. If its low it wont start.

I would call thor first then cummings

Jerry

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[Laco]

I would deal with Cummins, let them tell you where to take it. My wild guess would be a fuel or timing issue, but long distance diagnoses are notoriously inaccurate.

[Bob Denman]

Originally Posted by halfprice

Have you checked the oil level. If its low it wont start.

Another easy thing to check!
(Why didn't I think of it? )

[Oldchief]

Definitely check oil level in generator's motor. It has a low-oil shutdown feature that prevents motor from running or shuts it down if low on oil. Also, be sure the fuel in your coach is above the quarter full level. Most motor homes are designed so the generator can't drain your fuel tank and leave you stranded. So, generators won't run when fuel level gets below the quarter tank mark.

[Mo_Mike]

Another good test is pull the air filter and spray some starting fluid in and try and start.

If it starts then dies, you have a fuel supply issue. If it starts and runs you probably have a carb issue.

[ComputerChips]

I wouldn't take my dog house to CW to be worked on! Cummins/Onan will do the job right. I wasn't aware that the Onan generators have a 2 year/2000 hour parts and labor warranty. The 3rd year is just major components.
Mine would start and run to the point you release the start button and then die. Mine had stopped running while traveling. They said the brushes had arked and ruined the stator. $1400 deal covered during the last week of my warranty. Mine wasn't registered. I had to show documentation showing the date of purchase. They registered it and applied the repair bill to be covered. Didn't have to pay a dime.

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[Miramar Owner]

I have had good luck with Cummins. Expensive but done right the first time. If you decide to take it in for repairs I highly recommend Cummins.

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[MoldyOldPeach]

You might consider going to the Internet and entering the exact model number for your generator. Look for a manual for the generator that has a trouble-shooting guide. It may have some very simple steps you can try to eliminate the obvious or otherwise isolate the problem. It always helps when you’re talking to a technician to have ready answers about all of the steps you have tried, and that you have eliminated everything except the need for professional diagnosis. I have found this helpful on many of my Miramar’s systems (Leveling jacks, slide controllers, etc.). I always download and print hard copies for my “Rolling Library.” Just some thoughts. Good Luck and Happy Trails!

[jabrabu]

I made my original post for this thread back in June, and my generator is finally fixed. It took such a long time partly because we were using the RV a lot this summer, and also because the Cummins warranty authorization took a really long time. They did not want to pay for the removal and re-installation labor, but the generator had to be removed in order to work on it, and they eventually authorized the work.


I had the RV at a Camping World for some other issues along with the generator, and they said that they thought it needed an ignition coil and new control module, but they had to remove the generator to further troubleshoot it. Then I took it to a local generator shop, who is also a Cummins dealer, and they said the same thing.



The main problem turned out to be a cracked ignition coil, and the repair guy said the control module was also suspect and was replaced, so Camping World was correct in the first place. He said the coil may have always been cracked, and use & vibration eventually caused it to fail.