John Deere 110 TLB engine lugs when accelerating

[JD110TLBFan]

I have two late model John Deere 110 TLBs where the serial numbers are in the after range of (311032 - ), e.g. starting with digit T4 or higher, so there is no Engine Speed Sensor (LVA11184). The symptom I am experiencing with both is that accelerating from a stopped position to full speed (say at 2000 rpm) in B range noticeably lugs the engine, as does going up a slight slope in C range. It sounds like the engine is about to die. If I let off a bit on the accelerator, the engine recovers. And once full speed is achieved, the engine recovers. I do not detect any surging symptom, and the tractor doesn't stop (like when your butt comes off the seat sensor), and there is no fan belt squealing. Engine oil and transmission oil both are within acceptable level and very clear (was serviced recently, but this problem predates the recent service). Both the inner and outer air filters are brand new. The fuel shutoff valve is in the "ON" position. One had both its fuel filters changed and that didn't solve the issue.

This doesn't happen with my early model 110 TLB which has the engine speed sensor and presumably compensates for the added engine load with more fuel or something. On that early model, I can accelerate from stop to full speed without the engine sounding like it is about to die. One time I disconnected the early model's engine speed sensor (on the flywheel housing) and it behaved a bit like my late model is currently behaving where load causes lugging. So I know what the late models "should" sound like it it were operating properly. I bought the late models used so I don't know what they sounded like when new.

Given that the late models have no speed sensor, I did some searching online and I see others mention that Deere discontinued the speed sensor replacing it with something to do with the alternator.

So I have two questions for late model 110 TLB owners:

1. Has anyone with a late model 110 TLB experienced this engine lugging symptom and/or fixed it? Did it have to do with the alternator?
2. Can anyone with a late model 110 TLB confirm that they can set the RPM to 2000 and accelerate from stop to full speed in B range without the engine lugging (some minor reduction in RPM might be expected, but this is more than that)?

 

[RayIN]

Dirty governor??

 

[beenthere]

Assume you know you have the HST (hydrostatic) tranny and know how they function ??

If so the experience in C range shouldn't be a surprise.

The symptom I am experiencing with both is that accelerating from a stopped position to full speed (say at 2000 rpm) in B range noticeably lugs the engine, as does going up a slight slope in C range. It sounds like the engine is about to die. If I let off a bit on the accelerator, the engine recovers. And once full speed is achieved, the engine recovers.

 

[RayIN]

Assume you know you have the HST (hydrostatic) tranny and know how they function ??

If so the experience in C range shouldn't be a surprise.

That sounds like the old truckers adage; If you can't accelerate climbing a hill, drop down a gear.

 

[beenthere]

Hey Sedro Woolley, WA

What have you found out ?

 

[JD110TLBFan]

Well, I did some reading in the Technical Manual, and @RayIN it cannot be a dirty governor because there is no governor on early or late model 110 TLBs. Instead the function of the governor on late models is provided by the frequency of the output of the alternator. Page 314 of the technical manual mentions:

• For models (S.N. 311033-), the A1 HST controller determines engine speed from the tachometer output signal of G2 alternator (325B Grn wire)
• The anti-stall feature is part of the A1 HST controller program, which compares the signal from the R3 throttle position potentiometer (499 Wht wire) with the engine speed signal to control the PWM signal to the proportional drive solenoids.

Page 377 of the technical manual mentions:

• The HST controller uses a frequency input from the alternator to monitor engine speed. See "Charging Circuit Test" on page 242 to diagnose any problems with the engine speed input circuit.
  • Slow Idle Speed Frequency: 190 +/- 2.0 Hz
  • Fast Idle Speed Frequency: 520 +/- 2.0 Hz

As for @beenthere comment, since I have one 110 TLB that operates as I would expect in C range accelerating, the others that don't operate that way are indeed a surprise. To clarify, the issue happens in A, B, and C range just with different conditions (driving into a pile of dirt, flat ground acceleration, maintaining speed uphill, etc). I see your profile lists a JD_110. Is that a 110 TLB or the 110 lawn mower? If the TLB, what year is it (year is typically the number after the T in the serial number plus one added to it)?

I don't have the tools to do the potentiometer [re]calibrations mentioned in the technical manual. If I cannot figure this out on my own, I'll have to take it to the dealer to have them check the potentiometers, charge pump pressure, and proportional solenoid valves. What I can do, though, and plan to do when I get a chance, is to do what it mentions on page 379 of the technical manual to "Disconnect the X12 throttle position potentiometer connector to disable the load match feature." And then with it disconnected I will test to see how that changes the behavior. My thought is that if it doesn't noticeably make the behavior worse, then likely the problem is with that throttle position potentiometer or the alternator output frequency, but since that frequency is also the input for the tachometer on the dash and that gauge seems to be working fine then I doubt there is a frequency issue, but I suppose it could be an issue with a connector or wire connecting to the HST controller. The potentiometer is actually quite accessible and looks easy to replace and costs about $150, but then would require recalibration - so a dealer visit at that point.

If that test doesn't seem to help isolate the issue, then Page 427 of the technical manual mentions several more tests:

• Symptom: Low Power or Sluggish Response to Changes in Speed
  • Check hydraulic oil level
  • Is air in hydraulic system? If so, Bleed hydraulic system. See "Hydraulic System Bleed Procedure" on page 512.
  • Test charge pump pressure. See "Charge Pump Pressure Test" on page 429.
  • Check forward and reverse proportional solenoid valves. See "Proportional Drive Solenoid Test" on page 362.
  • Is HST pump or motor damaged or worn excessively?

 

[oldtimer 66]

Does one of these machine have load match and the other one does not, or neither and or both. If the load match is not engaged you will have this acceleration problem. Just saying.

 

[JD110TLBFan]

The Technical Manual sometimes used the words "load match" and sometimes "anti-stall". I'm assuming those are the same thing. All 110 TLB (early and late models) have the load match feature (early models via flywheel engine speed sensor and late models via alternator frequency). There isn't a switch to turn it on or off, it is always on (except if you disconnect the X12 throttle position potentiometer connector, which I plan to test to see what that does). My suspicion is that something isn't working properly with the load match feature because I agree with you that if the load match is not engaged then the engine will lug excessively under load. I know that for a fact because I have experienced it with my early model 110 TLB with the flywheel speed sensor disconnected.

 

[JD110TLBFan]

Update: I ran some tests this weekend.

1. Same problem occurs in forward and in reverse.
2. Fan belt was a little loose, so I tightened it and it made no difference.
3. Turning on all the lights doesn't noticeably change the reading of the tachometer.
4. I tried running a test of the HST relief valves (hold brake down and depress the forward pedal until you hear squealing), and did not hear squealing in forward or reverse - so the relief valves are not kicking in? I ran the same test on my "good" 110 and was able to hear the squealing in forward but not reverse.
5. I disconnected the throttle potentiometer and it made no difference. According to the Technical Manual, disconnecting the throttle potentiometer will disable the load match feature. Since disconnecting it made no difference in the behavior, to me this indicates that the load match feature isn't working with or without the potentiometer. Note that I disconnected it while the machine was running, and after reconnecting it I noticed a flash code of short-short-long-short (which the manual says is "Throttle Position Potentiometer") which didn't go away until I turned off the tractor and then restarted it. So now, as I'm typing this, I'm wondering if I should have shut off and restarted the tractor with it disconnected to see if that made a difference.

I made some video of the symptoms and a comparable video of the 110 that doesn't exhibit these symptoms for comparison.

Here is the video of the 2003 without the problem: https://youtu.be/_1xsAXh96_8
Here is the video of the 2005 with the problem: https://youtu.be/Uqx10gOY0PY