Cummings gasoline generator for 2015 ACE RV - Page 2

The Guidrys · 07-07-2016, 02:15 AM

I contacted my local Onan/Cummins service center today only to get an appointment mid August... Yep, thats right. I have 2 more trips planned before then, so I figure I'd take a shot a fixing the issue myself...

So I happened to have a 6' length of 5/16 fuel line and an inline fuel filter for my mower on the shelf. I went straight to the splice to assess it. Just like Winder1 described on his post, my 5/16 - 1/4 plastic splice on my fuel line was kinked, not enough to stop it from running while standing still, but enough to cut off fuel when driving on rough roads. I took out the 1/4 line completely, and used my inline filter to splice the hose together and attached the 5/16 line to the Onan fuel filter. Although the Onan filter is a 1/4 hose connection, I was able to tighten the hose clamp, and it doesn't leak. It took about an hour from start to finish. That is including opening and sipping a few cold ones in the process!

I did not have a chance to road test it, however, at least I have eliminated the $0.02 splice that was kinked. If it happens to be a fuel pump issue, then that will get fixed under warranty and will know that the new fuel pump will not be straining with a 5/16 line feeding it.

saddlesore · 07-07-2016, 04:43 AM

Hmmmm..

1)High ambient temps (95 deg +)= high fuel temps in tank
2) High engine box/compartment temps
3) carburetor engine
4) fuel pump struggling
5) engine stalls out
6) must wait for engine to cool down before it will restart.
7) using E-10 or higher mix of ethanol fuel

You might want to consider that combined with any fuel supply restrictions, kinks or bad splices that You may be having a "vapor lock" situation...

Try this..
shield (wrap) the fuel hose near the engine to the pump & carb with a bit of "tin foil" then cover that with a length of 1/2" ID hose using a couple of zip ties tighten to "just snug"... The fuel is trying to vaporize in the fuel line before it gets to the pump or carb. either place will screw the pooch.

Dwain65 · 07-14-2016, 10:21 PM

Updatee: I took the coach in for diagnosis last Friday and received an email a few minutes ago stating the unit was repaired under warranty (fuel pump). I will pick it up tommorow and speak to the tech about root cause..

D

wacdmc · 07-22-2016, 10:03 PM

Hey Larry - I have the exact problem with my generator. It started at 20 hours and is very intermittent. My generator engine also ran crappy at times, oscillating in RPM. It's been at Onan all week and of course, they can't replicate any problems. Did you find out what was causing the arcing sound?

winder1 · 07-22-2016, 11:29 PM

I just had my generator checked out by the ONAN dealer in SLC. I have now had my generator to 3 different ONAN dealers for the same problem, the generator shuts off while driving, and sometimes restarts, often won't. They have replaced 2 fuel pumps under warranty for me.

Last advice, from the third ONAN dealer in 9 months, take it back to THOR and have them INSTALL IT PROPERLY! It works fine on the bench, if it shuts off when you are driving, it is starved for fuel. Need more evidence? 2 ruined fuel pumps in less than 100 hours operating time.

ONAN, all 3, said they see this all the time. Fuel lines kinked, under sized, with a union installed, cable tied to death, on and on. Try getting THOR to actually FIX the problem, has been my challenge. They either can't, or won't. Can't see it any other way myself.

Dwain65 · 07-28-2016, 03:33 AM

Thanks for the update Winder1. I had replacement pump replaced last week. Then the day after, I fueled and packed her up and headed for Ft Smith Arkansas from Dallas. It ran perfect through all the mountains at temps in the mid 90's. When I pulled in to the campsite 4.5 hours later I applied the brakes to back up and you guessed it, ....she stalled. Didn't even attempt a restart. Plugged in to shore power and tried to forget it and enjoy the week. On Monday we headed to Lake Ouachita with temps in the low 90's with no problem. Today I left at 9 am and arrived at 5 pm with stop and go traffic (97 degrees max), no issues..however I did email Cummins and request a service appt.

Notes from tech:

All fuel lines look perfect. Unit mounted to close to door (2" from front of unit to door). Vent installed in door should help? Only item that has not been inspected/replaced is tank pickup tube.

Taking it back to Onan, calling Thor tomorrow to escalate

The Guidrys · 08-10-2016, 03:29 AM

Brought my coach in on Monday to diagnose/repair my "code 36" that occurs when I hit bumps in the road.

I got a call from the dealership that it was fixed. It was a bad float in the carburetor causing it to dump fuel in the cylinder and thus flooding the motor causing it to stall. How he diagnosed it was to shake the unit on its springs vigorously. He said the fuel poured out of the air filter. They replaced the entire carburetor to alleviate the issue...so it seems...

I pick it up with my CRV in tow Monday evening. I take the LONG way home, interstate to state road to parish roads, crossed many bridges, rail roads, and purposely hit pot holes to see if it indeed was fixed. It wasn't until I got a mile from my driveway, after getting off a bridge the damned thing stalled... yep... Code 36. I called the service advisor immediately to let him be aware of the situation.

I returned the coach this morning, and ran the generator the entire way hitting pot holes, bumps, crossed tracks and purposely attempted to stall the sucker out. Of course, no luck. Ran perfectly. Talking with the advisor, they are going to contact Onan/Cummins corporate HQ to discuss my specific case. Im starting to think it maybe since my unit is mounted at the rear of my coach, it is bouncing more than it was designed to while in motion. My two previous coaches, they were mounted mid chassis and I had NO issues with them stalling out. Im curious to see what the corporate response will be from Onan/Cummins.

winder1 · 08-10-2016, 03:53 AM

My generator failed again as well. It has NEVER worked without stalling every 2-3 hours. This time it was when we FINALLY started on the vacation trip we bought this for, back in October of 2015. It has been in the shop virtually the entire 9 months.

This time the generator failed in 108 degree heat driving in Nevada. Made for a real pleasent trip. We got to Salt Lake City and tried to get the THOR dealer to look at it. They wouldn't even bother, saying if I didn't buy it from them, 6 week wait at least. THOR Warranty Service was their typical waste of time to call, no help whatsoever. I can't imagine what THOR thinks "good service" must mean.

The ONAN dealer in Salt Lake was the opposite of THOR. When I called they said 2-3 weeks for an appointment, but when I explained my predicament they had me bring it in first thing in the morning. This is the THIRD ONAN dealer I have taken it to. The diagnosis? The same as at the first 2, there is nothing wrong with the generator, take it back to THOR and HAVE THEM INSTALL IT PROPERLY!

Much easier said than done, as it's been in the shop 3X's already, for weeks total, and EVERY time I have driven it, the generator has failed.

It has company. The auto levelers have also NEVER worked, it burns up house batteries, runs batteries flat, and did I mention the battery control box has also been replaced several times?

I would love to use my MH just once, and have the generator not quit working, and the levelers work. Seems beyond THOR to make it happen.

JamieGeek · 08-10-2016, 10:18 AM

Quote:

Originally Posted by The Guidrys

Im starting to think it maybe since my unit is mounted at the rear of my coach, it is bouncing more than it was designed to while in motion.

On the Axis/Vegas 24.1 models the generator is mounted at the very back end of the coach well behind the drive wheels. Aside from a defective fuel pump our generator has not stalled at all while going down the road (or otherwise).

The Axis/Vegas units don't really have as much rear overhang as other campers though which may slightly minimize the bouncing.

Chance · 08-10-2016, 12:42 PM

Quote:

Originally Posted by JamieGeek

On the Axis/Vegas 24.1 models the generator is mounted at the very back end of the coach well behind the drive wheels. Aside from a defective fuel pump our generator has not stalled at all while going down the road (or otherwise).

The Axis/Vegas units don't really have as much rear overhang as other campers though which may slightly minimize the bouncing.

If bouncing is a factor (and I'm not saying it necessarily is), then other factors could be contributing as well. As you mention, the much longer rear overhang can't help.

In addition, your motorhome is on a 12,500-pound chassis whereas the 34F is listed as a 22,000-pound chassis. Whether that makes it harsher at back also depends on motorhome weight and spring rates.

And when it comes to vertical movement, we can't ignore flex in the chassis itself. The F53 chassis is stiffer than the E-Series, but not enough to make up for the extra weight and length in this case.

In general: I would ask Onan what they want as a proper installation. If it's not installed correctly, then request they state exactly what is out of spec.

That three Onan dealers came up with same answer is not that surprising to me. They may be reading off the same notes that the first one wrote. One of the downsides of computerized world is that it makes it more difficult to get an unbiased second opinion from same company.

**fhenn** · 08-10-2016, 01:23 PM

I would check the fuel lines and fittings, there have been reports of some of these that have been twisted. and some lines and fittings were to small

Dwain65 · 10-22-2016, 04:17 AM

Anyone found a resolution for this issue? I currently have mine at the local ONAN service center after installation specifications were confirmed by Thor Service dealer. Now outside temperatures are only in the 80's so she will run all day without a stutter.

My next question is could this be the ECM? Possibly getting heated up and not supplying the proper voltage to fuel pump?

Winder any traction on your coach??

D..

Joe-FL · 10-22-2016, 01:46 PM

Quote:

Originally Posted by saddlesore

Hmmmm..

1)High ambient temps (95 deg +)= high fuel temps in tank
2) High engine box/compartment temps
3) carburetor engine
4) fuel pump struggling
5) engine stalls out
6) must wait for engine to cool down before it will restart.
7) using E-10 or higher mix of ethanol fuel

You might want to consider that combined with any fuel supply restrictions, kinks or bad splices that You may be having a "vapor lock" situation...

Try this..
shield (wrap) the fuel hose near the engine to the pump & carb with a bit of "tin foil" then cover that with a length of 1/2" ID hose using a couple of zip ties tighten to "just snug"... The fuel is trying to vaporize in the fuel line before it gets to the pump or carb. either place will screw the pooch.

This could easily be causing the problems for many of these failures. A friend of mine several years ago had an issue with his 40' express cruiser stalling. It would always do it when temps we 90 and higher. With twin V-8 engines down in the hull of a large boat it get warm, just like a small gen set confined in a tight storage compartment.

He re-routed his fuel lines further away from both engine and wrapped/insulated them. Problem solved, it never stalled again. So are a lot of these gen set problems due to hot fuel delivery lines rather than just overheating generator motors?

Dwain65 · 02-01-2017, 01:20 AM

Well gents after 8 trips to the dealer and Onan I have decided to add a low pressure push pump to my gen. The primary pump has been replaced 4 times now and I have added a door vent to no avail. I still continue to hear random pump clicking even at lower outdoor temps. I will post updates after my trip post install this weekend

SuperD · 02-01-2017, 02:25 AM

I don't remember if it was on the Thor forum or iRV2 forum, there was a thread about gen sets overheating. The fix was to get more air to the gen by installing a louvered panel in the access door, if I remember right this cured the overheating problem. For those of you that are having a continuous shut down problem I would check in to this. Might help!

Dwain65 · 02-01-2017, 02:42 AM

Thanks. I have heavily modified the door opening to allow outside air in to the generator per Thors recommendation but still have the chatter (losing prime) sound from the gen fuel pump at cool temperatures. I am out of options...

Quote:

Originally Posted by SuperD

I don't remember if it was on the Thor forum or iRV2 forum, there was a thread about gen sets overheating. The fix was to get more air to the gen by installing a louvered panel in the access door, if I remember right this cured the overheating problem. For those of you that are having a continuous shut down problem I would check in to this. Might help!

Hittntherooad · 02-01-2017, 02:55 AM

Quote:

Originally Posted by Dwain65

Well gents after 8 trips to the dealer and Onan I have decided to add a low pressure push pump to my gen. The primary pump has been replaced 4 times now and I have added a door vent to no avail. I still continue to hear random pump clicking even at lower outdoor temps. I will post updates after my trip post install this weekend

There is a vent made especially for the Onan 4000. It has a boot that forces the air from outside of the RV to keep hot air from under the RV from being sucked into the intake cooling air. Here is a pic of me installing the boot.

Hittntherooad · 02-01-2017, 02:58 AM

Finished vent. No problems since. Thor doesn't recognize this as a problem. The intake air only has about 2" air space between the back of the bay door and sucks hot air from under the RV from the exhaust and engine. I was getting the 36 code in hot weather. I had to get my vent from a Forest River dealer.

SuperD · 02-01-2017, 03:13 AM

I knew I had seen the vent somewhere, just couldn't remember where, oldheimers catching up with me I guess! Hittntheroad, thanks for chiming in, will hopefully help some of these people with their problem. By the way, you did a great job on that installation!!!

Hittntherooad · 02-01-2017, 03:29 AM

Quote:

Originally Posted by SuperD

I knew I had seen the vent somewhere, just couldn't remember where, oldheimers catching up with me I guess! Hittntheroad, thanks for chiming in, will hopefully help some of these people with their problem. By the way, you did a great job on that installation!!!

Thanks. I believe the majority of the problems people are having is heat related. Mine only shut down when temps were in the 90's. The extreme heat may be causing the fuel pumps to fail. Also the exhausting air from the generator comes out the bottom of the generator and could be sucked right back in to the intake. Just putting a vent in the door helps very little. The key is the rubber boot between the generator and back side of the bay door. Hope this helps someone out.

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