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.