Throittle Issue

[Got2BTru]

I have a Mahindra 2555 HST that I'm having a recurring issue with (been to the dealer now 3 times, though he claims he can't replicate the problem).

I'm out brush hogging on our 32 acres and after and hour or two if I have to stop to feed/water the dogs, replace a shear pin, etc. I lower the throttle to 800 or so RPM. When I get ready to get back to work, it won't go any higher than 1400 RPM (2400 needed for PTO Brush Hog speed).

Not sure if I can post a video or not, but I'll try..

 

[Cramby]

Have you checked your throttle linkage for slipping?

 

[jmh1783]

That's pretty weird. I think these tractors have electronic throttles. I wonder if the computer thinks somethings wrong. Have you tried manually actuating the throttle on the side of the engine...to Cramby's point to make sure it isn't slipping. Also what happens if you let it sit at 1400 rpms for awhile, does it start to rise after awhile?

 

[tkevan]

http://www.tractorbynet.com/forums/mahindra-owning-operating/348870-2555-throttle-response-3.html

 

[Got2BTru]

http://www.tractorbynet.com/forums/mahindra-owning-operating/348870-2555-throttle-response-3.html

TKEVAN,

I have checked this, thank you...it appears to be in the neutral position (I've NEVER moved it to be honest). What's interesting is as I read through that thread, I JUST had the exact other issue they referenced, the MIL check engine light error, which coded out to be a dirty EGR. My dealer told me the same thing, I need to run it at a higher RPM, I wasn't working it hard enough...

Have you checked your throttle linkage for slipping?

CRAMBY,

I don't know how to check that personally, but I would *assume* the dealer did it any of the 3 times he had it in his shop?

That's pretty weird. I think these tractors have electronic throttles. I wonder if the computer thinks somethings wrong. Have you tried manually actuating the throttle on the side of the engine...to Cramby's point to make sure it isn't slipping. Also what happens if you let it sit at 1400 rpms for awhile, does it start to rise after awhile?

JMH1783,

Yes, I can pull on the throttle cable manually and can increase the throttle speed.

If you notice from the video I took, the first 1/4 pull of the lever brings the tractor to 1400 RPM, but then simply nothing after that...it's ALWAYS happened after I've been running the tractor for a couple hours and stop/pause. If I let it cool down overnight it's fine the next time I go to use it.

 

[Usmcsrt1]

I've had that issue with my 16' 2555hst after bush hogging for a while also. I just thought it was due to getting too hot so I would let it sit for a couple minutes and restart it and it would go all the way to pto speed. I've got approximately 42 hours now and it has happened 3-4x, but not as bad as your video shows. It would stop at around 2000 rpm or so.

 

[jmh1783]

There's another thread here on an EGR problem with the 2555s. Not sure if this is the same problem or not. Keep us posted. The 2555 is on my short list.

 

[Got2BTru]

I did have an EGR issue, the dealer came out and cleaned it out. But this is unrelated to my throttle issue.

Worked for about 3 hours today...never let the throttle below PTO speed, even when I got out of the tractor a couple of times...I was fine all afternoon until I wrapped it up and tested....sure enough, when I dropped it below PTO speed, it would NOT go higher again.

I can't see how it's not something overheating...

 

[dickfoster]

I did have an EGR issue, the dealer came out and cleaned it out. But this is unrelated to my throttle issue.

Worked for about 3 hours today...never let the throttle below PTO speed, even when I got out of the tractor a couple of times...I was fine all afternoon until I wrapped it up and tested....sure enough, when I dropped it below PTO speed, it would NOT go higher again.

I can't see how it's not something overheating...

Humm, beginning to wonder if it's not something related to the RPM sensor or the ECU heating up and weirding out. Of course it could just as easily be a related connection.

 

[Navasot]

Hows you hyd. fluid level look

 

[Navasot]

How big of a mower

 

[Got2BTru]

Hydro level is fine, mower is 6' Bush hog...

 

[Got2BTru]

My dealer just reached out to me with this:

Chris I have spoken to a service rep he wants me to reprogram throttle and check throttle cable location on fire wall

I'll let you all know how it works...please keep me updated if you find something different!

 

[Got2BTru]

He worked on it and here's what he said...

Hi Chris I work on tractor I believe I fixed throttle problem I rerouted throttle cable it had a very sharp bend when it came out of fire wall after it got warm I could see ware it might collapse and not let it travel full distance I'll be back out on Friday to reset the ecu I made the MIL light come on didn't have my computer with me Thanks Todd

We'll check her out this weekend I guess!

 

[FastJimmy]

Is he going to refllash ECU or just reset it to clear MIL?
Thanks
F J

 

[dickfoster]

Is he going to refllash ECU or just reset it to clear MIL?
Thanks
F J

A reset is usually just clearing the codes and the check engine light. They will often reset by disconnecting the battery for a few minutes or of course using your own scan tool. Scan tools are cheap enough that everyone should own one for their tractor, cars, trucks, etc. Every car and most trucks produced since 1996 has OBDII or CAN so it wouldn't be wasted. I have two and keep one of them plugged into the truck where it supplies info for gauge readouts that I wish the truck had from the factory.

 

[FastJimmy]

dickfoster,
I suspected that it was simply a clearing of the MIL code and not an ECU re-flash that was being referred to.
However, as you said a code can be cleared by simply disconnecting the battery for a brief time, I couldn't see why he would make a special trip back with his computer just for that .
F J

 

[Got2BTru]

Last time the MIL came up, I had a dirty EGR...he cleaned it and then reset the code, not re-flash.

 

[dickfoster]

dickfoster,
I suspected that it was simply a clearing of the MIL code and not an ECU re-flash that was being referred to.
However, as you said a code can be cleared by simply disconnecting the battery for a brief time, I couldn't see why he would make a special trip back with his computer just for that .
F J

I don't know if it works for Mahindra tractors but I know it does for my Toyota truck and most other cars and trucks. Before I got my first scan gauge that's how I reset the CEL. The trouble with using that method is that many ECUs self learn a bit by trimming the factory base maps over time. When you pull the power you reset the codes but you also lose all of that fuel and timing trim info so the ECU has to start trimming from the base map all over again. With a scan guage you can just read and reset the codes without losing any trim data.

 

[Got2BTru]

Guys, I *assume* resetting of a MIL code would do nothing more than if you did the same thing in a car. After the vehicle goes through it's next cycle, it would trip again and come right back...