Engine RPM Not Coming Down

[mculik5]

Experienced something strange on my B2650 today...

I was dumping of bucket of dirt on a pile and had the loader up in the air. All the sudden, the engine RPMs jumped about from about 1700 to about 2000. I finished dumping, backed up, lowered the loader and idled the engine.

But instead of the normal 1100 RPM idle, it was idling at 1300 RPM. After about a minute or so, the idle had settled back to normal.

Then, a bit later, the same thing happened. At that point I had the RPMs up higher and I idled the engine with the loader in the air. The RPMs only came back to 1700 with the throttle completely closed. Interestingly, as soon as I touched the loader to bring it down (with the throttle closed) the RPMS dropped right down to normal 1100 RPM idle.

Nothing visibly wrong with the tractor that I could tell and the engine was running completely fine at all times...just weird RPMs.

Any ideas? Thanks. Happy Easter if you celebrate!

 

[mikester]

First things I'd check
1. bumped your throttle lever
2. spring or linkage issue
3. now check your cell phone

 

[Runs With Scissors]

Is your machine new'ish?

Could it be that "re-gen" thing that happens every so often?

 

[sheepfarmer]

Is your machine new'ish?

Could it be that "re-gen" thing that happens every so often?

Not on a B2650. Even though a fairly new model. Below the horsepower cutoff for dpf filter needed.

 

[sheepfarmer]

Experienced something strange on my B2650 today...

I was dumping of bucket of dirt on a pile and had the loader up in the air. All the sudden, the engine RPMs jumped about from about 1700 to about 2000. I finished dumping, backed up, lowered the loader and idled the engine.

But instead of the normal 1100 RPM idle, it was idling at 1300 RPM. After about a minute or so, the idle had settled back to normal.

Then, a bit later, the same thing happened. At that point I had the RPMs up higher and I idled the engine with the loader in the air. The RPMs only came back to 1700 with the throttle completely closed. Interestingly, as soon as I touched the loader to bring it down (with the throttle closed) the RPMS dropped right down to normal 1100 RPM idle.

Nothing visibly wrong with the tractor that I could tell and the engine was running completely fine at all times...just weird RPMs.

Any ideas? Thanks. Happy Easter if you celebrate!

That is weird. Only suggestion i have is to lubricate all of the parts of the the throttle connections. They get sticky. Can't figure out connection to loader position unless there is a stick in there somewhere.

 

[cthomas]

Check oil level to make sure not overfilled.

 

[number two]

Maybe the throttle friction adjustment is too tight?
Good Luck!

 

[#40Fan]

The hand throttle isn't directly connected to the linkage at the engine.

Here are a couple pictures. First shows the hand throttle that you'll move while in the seat. The piece circled in red (in both pics) acts upon the piece pointed out with the green arrow. You'll notice in the second picture, the rod goes through a couple holes and has a spring that helps with pulling it back when the hand throttle is moved. I'd check that area out for binding.

As for why it goes back when you operate the loader.....Maybe there is some binding that only happens when the loader is off the ground. Does the bucket sit level when fully lowered?

 

[Joisey]

The only time I had an experience with a diesel that wouldn't return to idle as normal was with my VW diesel Rabbit. I was driving to work and about half way thru a long left hand bend when the engine just took off on its own. I went from 55 mph to almost 70 when I pushed in the clutch. By that time I was thru the turn and the revs dropped to normal. I thought it was a fluke until it happened the next three days on the way to work, but never on the way home.

It turned out that the engine was spewing fuel vapor that collected in the air box behind the filter. There were drain holes to the individual intake port runners at both ends of the air box. The vapor would condense into liquid and lay in place until I took that long left hand turn which had a fair bank angle to it. The bank angle caused the liquid to run into the intake runners, giving the engine more fuel and causing a runaway.

I checked the compression and it was 50 pound above minimum, but the engine had begun to use oil, so I pulled it and had it bored and had new valves and guides installed in the head. The problem never returned for the 200K I put on after rebuild.

I'm not saying THIS is your problem, but it may be something to look at. Best of luck to you.