Montana 4340C ... RPM's Fluctuating.

[blueriver]

4340 C with 1500 hrs ... this time of the year it sets at the pond hooked to an irrigation pump ... runs 10-12hrs on a set. The rpms are set at 17-2000 depending upon the total distance of my discharge hose. The a/c is off, the radio is off and all the doors and windows are open.

I just noticed in the last couple days it will purr along like a kitty in a milk parlor and then for a split second a slight change in the engine sound ... the rpm's go up and I mean a split second ... then she purrs along for about 10-12 minutes and then the same fluctuation in the rpms. I noticed today when that happens a small puff of black smoke ... its fast changing by the time you hear it its over.

What do the experts think ... maybe a valve hanging up?

 

[pacerron]

4340 C with 1500 hrs ... this time of the year it sets at the pond hooked to an irrigation pump ... runs 10-12hrs on a set. The rpms are set at 17-2000 depending upon the total distance of my discharge hose. The a/c is off, the radio is off and all the doors and windows are open.

I just noticed in the last couple days it will purr along like a kitty in a milk parlor and then for a split second a slight change in the engine sound ... the rpm's go up and I mean a split second ... then she purrs along for about 10-12 minutes and then the same fluctuation in the rpms. I noticed today when that happens a small puff of black smoke ... its fast changing by the time you hear it its over.

What do the experts think ... maybe a valve hanging up?

Your wasting too much time listening to a tractor while the hog shed is waiting.

 

[Texasgreen]

My 4940C will do the same thing. It's as like you just taped the throttle override peddle. Mine stopped doing that after I changed the fuel filter and replaced it for some reason.

 

[blueriver]

Your wasting too much time listening to a tractor while the hog shed is waiting.

Oh now ... somedays it seems if alot of things are waiting!! First time I heard it I thought what the heck and now I'm tuned into it and can hear it in my sleep!!

 

[blueriver]

My 4940C will do the same thing. It's as like you just taped the throttle override peddle. Mine stopped doing that after I changed the fuel filter and replaced it for some reason.

Interesting ... I replaced my fuel filter about 60 days ago and NOW I'm hearing it.

 

[Texasgreen]

I'm went with a Wix fuel filter. I'm sure it has nothing to do with it. I had 512hrs on the original fuel filter before I changed it out and my tractor stopped doing the rpm spike thing.

 

[blueriver]

I'm went with a Wix fuel filter. I'm sure it has nothing to do with it. I had 512hrs on the original fuel filter before I changed it out and my tractor stopped doing the rpm spike thing.

Well I am hoping its fuel/filter related ... going to get and change the filter again and add some diesel additive.

 

[pacerron]

Well I am hoping its fuel/filter related ... going to get and change the filter again and add some diesel additive.

Maybe you should make your own diesel with piggy pooh

 

[blueriver]

Maybe you should make your own diesel with piggy pooh

That may make things "squeal" ....

 

[Stampeder]

When was the last time you cleaned your injectors? Throw some diesel additive in. At 1500hours I'm sure they can use the cleaning. I've got over 500 hours on my 4940C and I am about to change my fuel filter also. Incidentally, I switched to synthetic a long time ago and it causes my Montana to run A LOT cooler in the summer. Lot less friction.

Let us know about the fuel filter change. BTW I too use WIX filters on my tractor and my Ford dually diesel. Really like them.

 

[Sackett2]

When was the last time you cleaned your injectors? Throw some diesel additive in. At 1500hours I'm sure they can use the cleaning. I've got over 500 hours on my 4940C and I am about to change my fuel filter also. Incidentally, I switched to synthetic a long time ago and it causes my Montana to run A LOT cooler in the summer. Lot less friction.

Let us know about the fuel filter change. BTW I too use WIX filters on my tractor and my Ford dually diesel. Really like them.

how often would you use the fuel cleaner? have 500 hours on mine AND with synthetic, what oil change interval do you use?

 

[ibhere]

My 4940C started doing the same thing after I changed fuel filter. Manual says air trapped in fuel system is culprit. Hope this helps!

 

[blueriver]

how often would you use the fuel cleaner? have 500 hours on mine AND with synthetic, what oil change interval do you use?

I started using it on every fill ... just a little per the instructions. I like 100 hrs for the oil change... sometimes it runs over. I know some folks call me crazy and suggest a couple hundred ... Oil is cheap compared to engines. Rottella 15W 40.

 

[blueriver]

My 4940C started doing the same thing after I changed fuel filter. Manual says air trapped in fuel system is culprit. Hope this helps!

Air trapped ... interesting and I wonder how long it remains trapped? I would think after several tanks it would be gone. I have in the last 14 days run several gallons thru her on the irrigation pump. I run right at 1 GPH at 2000 rpms. The outdoor temps make me nervous with her setting at the ponds edge ... I check things often and all is well.

 

[Stampeder]

I started using it on every fill ... just a little per the instructions. I like 100 hrs for the oil change... sometimes it runs over. I know some folks call me crazy and suggest a couple hundred ... Oil is cheap compared to engines. Rottella 15W 40.

Switch to Amsoil. They have a service where they will check your oil for you for free and determine when you need to change it.
I am going to switch mine from Rotella to Amsoil. I've run Rotella for a few years now and go 250 hours between changes. I do however change oil filters every 100 hours. I'm also investigating adding the Amsoil bypass filter system. It comes highly recommended for my Ford F350 dually diesel and if it's good enough for my truck it will do wonders for my tractor. Only problem I have is where to conveniently mount the 2 micron filter.
The bypass system cleans you oil and really helps with the lubrication of the injectors (so I am told).
Food for thought.