RX6620 surges - Pricey Accelerator Potentiometer

[Triple B Ranch]

A few days back the unit started surging with the check engine light flashing and eventually went into limp mode at 1400 rpm and no throttle control. Dealer says its the potentiometer attached to the foot accelerator. The Kioti part for the fix is $968 plus labor etc.

Have others encountered this problem? I'm questioning whether to dump my Kioti and go with another brand soon. The combo of pricey parts and unreliable equipment is becoming painful. Add to that no A/C once again (compressor seal) and I'm in for a new compressor too another $1,100 in parts.

Thanks for any insights, another $3k down the toilet...

 

[RustyA]

Perhaps the defective sensor has a mfg number on it that can be crossed over to a less expensive part? I'm guessing that part is sourced from a supplier?

 

[Robin Veerman]

I take it that there’s no warranty left? How many hours on the tractor?

 

[Fuddyduddy1952]

Dealer says its the potentiometer attached to the foot accelerator.
Isn't that the same thing as an automotive throttle position sensor (drive by wire)?
If it were mine I'd buy a shop manual and/or simply find out where the sensor is and remove it. A potentiometer is another name for variable resistor. A resistor with "wiper" so three instead of two leads. Throttle lever instead of a mechanical linkage it goes to the potentiometer wiper. This is wired into the computer to control engine speed.
I'd want to have sensor removed and on my workbench with a multimeter on ohms scale.
Measure resistance between leads as well as measure while moving lever (wiper).
Look up potentiometer or variable resistor. See how simple it is. Say it's a 10K pot (10,000 ohms). With wiper in middle it will be 5K from wiper to either side. Moving wiper ohms decreases one side as it increases the other. Very simple device. If yours is bad it won't do that, it may be open. Spray with electronic contact spray unless it's sealed (it probably is) and try it.
If bad take it to an auto parts store if they'll let you match it with one. The key is you must know the resistance. If it's bad (I wouldn't just assume their diagnosis is correct) but IF it's bad and you can carefully open it you should be able seeing what's wrong or at least measure resistance.
Any sensor that correct resistance with same lever (wiper) movement would work fine as long as wiring connector plug is the same.
A service manual would show removal procedure. Hopefully it's not hard to get to.

 

[TN8Man]

On mine if my tractor goes into limp-home mode relating to the throttle pedal sensors (HST Linked Pedal) that indicates both potentiometers ACC1 and ACC2 have malfunctioned. I would be looking for a bad cable connection first.

 

[ruffdog]

If the potentiometer is replaced, I'm thinking that it would have to be re-calibrated to the computer. Would that procedure need to be done by the dealer?

 

[Fuddyduddy1952]

If the potentiometer is replaced, I'm thinking that it would have to be re-calibrated to the computer. Would that procedure need to be done by the dealer?

It wouldn't. Not that I can see.

 

[Fuddyduddy1952]

I assume dealer is same place you bought tractor. I know what I'd do. I'd go there with my phone on camera mode and multimeter. At parts department say my RX6620 needs throttle sensor and if they have one. If so, he/she will lay on counter. I believe I could take a picture of it and box with part number so they'd never know. Then simply ohm it out. It only takes a minute, being nice they shouldn't mind. Just say you want to compare with yours making sure it's bad.
If they don't have it, I'd have them look it up, again getting part number. Also get their price. Thanks...then on to service department. Ask if they can show you where it is.
Know you know resistance, where it's located and part number. Check yours (simply unplug & measure). If yours IS bad see about ordering one...price shop.
If not too expensive & difficult replacing I'd do that.
Shown is a $12 Ford one. Three terminals. Yours should be similar. It must be correct resistance and 3 leads correct (each end and wiper).