RTV 1100 won't run in cold weather

xerman · Dec 20, 2013

I have a RTV 1100 with a 78" Boss snow plow, 5 years old, 200 hrs. Love this machine but I have had trouble getting it to run in cold weather. This has been going on for the last 2 winters. It would start, idle and warm up just fine but within 15 or 20 minutes of running it would die. The dealer kept insisting that it was a fuel issue, bad fuel, water in the fuel, fuel gelling etc. I posted the issue on this forum and followed all the suggestions. I drained the fuel system, installed a separation filter, bought a Mr. Funnel to run the fuel through before putting it in the machine, used a fuel additive and have kept the tank full right to the top. I was sure I had the issue resolved after all that. Well a couple of weeks ago we got our first cold snap along with a foot of snow. Within 30 minutes of running the same issue returned. I called the dealer had him pick up the machine. Told him to keep it as long as necessary to get the issue resolved once and for all. Just got the machine back and plowed for over an hour in cold weather. It ran just fine and the issue seems to be resolved.
I am just a little concerned about what they did to fix it. They said they tested the fuel and there were no fuel issues. The mechanic took the machine out, ran it and it did exactly the same thing for him. He said that there was to much air getting into the fuel system and the machine was getting fuel starved and dying out. He crimped off the vent line from the top of the fuel tank and the problem was gone. He then removed the crimp and the problem returned within 5 minutes. His final fix was to put a shut off on the vent line. Told me to keep the vent line closed off unless I was changing the fuel filter, then open the line to allow fuel to fill the filter bowl. The only thing I can figure is that the original fuel filter was an in-line filter with a fuel line in and a fuel line out. The new separation filter has 3 lines, fuel in, fuel out and a vent line. Is it possible that with an additional vent line there is to much venting? I am thrilled that I can now use the machine for plowing snow but am a little concerned about keeping a vent line closed off.
Any thoughts about why this fix worked and is there anything I should be concerned about?

SpudHauler · Dec 20, 2013

Would like to see how the vent line from the new filter system works.

Can you provide a name for the filter?

It almost sounds like there is an air leak in that line somehow.

What would happen if you went back to the original in/out filter system?

I installed a Kubota fuel/water system that had one inlet and one outlet. It worked poorly until I found the problem, that the new line from the tank was kinking and cutting off the fuel after 10-15 minutes. Stop and wait 5 minutes you could sometimes run for 1/2 hr. Fix was a 90 degree fitting to relieve the bend in the hose.

Not sure where the filter vent is venting to, but with the tank vent shut off, it normally should starve the system because the fuel tank would eventually air lock. So this filter vent is the big question.

Why didn't he just shut that vent off?

Sorry just more questions.

Thinking your original issue was just water in the fuel, you fixed that, now the new filter introduced a new problem. Most filters don't have a vent line, just a bleed screw that is opened to purge the air when changing filters.

I do not like the fuel tank shut off fix. To me it is a workaround for a problem not yet fixed.

Keep digging.

timswi · Dec 20, 2013

SpudHauler said:
Would like to see how the vent line from the new filter system works.

Can you provide a name for the filter?

It almost sounds like there is an air leak in that line somehow.

What would happen if you went back to the original in/out filter system?

I installed a Kubota fuel/water system that had one inlet and one outlet. It worked poorly until I found the problem, that the new line from the tank was kinking and cutting off the fuel after 10-15 minutes. Stop and wait 5 minutes you could sometimes run for 1/2 hr. Fix was a 90 degree fitting to relieve the bend in the hose.

Not sure where the filter vent is venting to, but with the tank vent shut off, it normally should starve the system because the fuel tank would eventually air lock. So this filter vent is the big question.

Why didn't he just shut that vent off?

Sorry just more questions.

Thinking your original issue was just water in the fuel, you fixed that, now the new filter introduced a new problem. Most filters don't have a vent line, just a bleed screw that is opened to purge the air when changing filters.

I do not like the fuel tank shut off fix. To me it is a workaround for a problem not yet fixed.

Keep digging.

Agreed...Mine is 4 years old and just like Kubota created it with no add-ons except for the stereo...Never had the issues the OP stated...I plow in some seriously cold weather for 2+ hours at a time.

art · Dec 20, 2013

Try power service and you should be good. You have not put enough fuel through it and it should be the winter mix!

xerman · Dec 20, 2013

The fuel separator filter I put on is from Kubota. When I thought I was having water in the fuel issues I wanted to replace the original in-line filter with a separator filter. There was no such thing listed in the parts manual for an RTV 1100. The dealer found it listed in the RTV 900 parts manual. He said it would work fine on the 1100. It did fit just fine with all the threaded holes lining up perfect from the filter assembly to the bracket on the machine. I was having a difficult time (at my age) trying to install the new filter assembly. (very cramped area to get it into) so I had a nephew of mine install it for me. When I asked him what the third line from the filter assembly was he said "it is a vent line and it hooks up underneath here". Exactly where he hooked it up to I don't know.
But when the dealer had the machine they said that the separation filter was installed and hooked up correctly. I am concerned that plugging the fuel tank vent line is just masking the real problem. But after having the machine parked and unable to use it last winter I am thrilled to be able to plow in the comfort of the cab rather than being on one of my open tractors.

David_Kb7uns · Dec 20, 2013

Please read this carefully.

If you are using the filter kit for the RTV900, it would need extra hoses to install correctly. The RTV 1100 that I have was from the 2007 production time. Yes there are holes in the frame to mount the kit and it was undocumented on its use on the 1100 at the time I got it.

The old inline filter ran from right to left in fuel flow looking at the right inner frame rail.

The water separator has three connections, from looking as it is mounted the left is the in and the right is out with the top being the self bleed line to the tank.

From the factory the tank has a bottom fuel suction and a top return from injector and pump return. There is a unused smaller return that is capped, I used this is for the filter bleed line.

To do the install correctly I had to get longer hoses and run the tank line around to the left side of the filter and the outlet on the right to go around to the engine and get a longer bleed line to go to the tank. I used the separate vent fitting that was capped off as I did not want an airlock hooking to the return line from the injectors and pump.

When the filter bowl is removed a plunger pops out and shuts the fuel off, when it is reinstalled it pushes the plunger and fuel flow by gravity into the filter bowl with air going up the bleed line to the tank this makes the system self bleeding.

Check the filter connection to make sure they are not reversed on the filter body as if they are you could suck air from the tank( this may be why crimping bleed line makes it run ok).

Hope I have not left anything out but my filter works real good and no more frozen filters from the water being trapped in the inline filter body.

David

SpudHauler · Dec 21, 2013

David,
Mine was a 900 accessory that Kubota once listed that I too had mounted on my 1100. Mounts real nice on the frame like you said. Can't find a picture, but didn't think it had a third line, poor memory and no RTV so can't check.

I went from the tank with a short line, 90 degree fitting, then to the inlet side of the filter which when mounted was to the front. Tubing they provided then went from the outlet side of filter to the fuel pump. The 90 degree fitting fixed a fuel line kinking problem and after that no problems.

Do you have pictures of yours?

David_Kb7uns · Dec 21, 2013

No pictures just remember having to remember pulling the tank loose to put the longer hose on the fitting coming off the tank because I did not want to loop it over the frame rail to keep the self bleed of the filter housing. But most people could just put the filter in there and not reverse the hose connections and that means that the fuel pump will be sucking fuel in the reverse direction through the filter element and also having suction on the vent line going to the top of the tank and why crimping the vent makes it run correctly.

David

xerman · Dec 21, 2013

David_Kb7uns was absolutely right on. He hit a home run with that response. I purchased the 1100 in June '08 about the time he got his. I went out and checked how the lines are currently connected. The tank line enters the separation filter on the right and the line to the fuel pump is on the left. The Kubota rep got it running by putting a shut off the the vent line from the top of the filter to the fuel tank. For right now it is finally working. Once we get a break in the weather I will be getting some longer fuel lines and hooking it up as per David _Kb7uns. Dave your explanation was excellent. You should be a technical writer for Kubota. I just can't thank you enough.
Also, thanks to SpudHauler and all the rest who responded.