While moving brush with grapple for about 30 mins, I attempted to raise rpm's. With lever all the way down to full throttle, it would not go past 1500. I turned off and restarted 3x. No change. I turned it off and waited approximately 30 mins, and started her up and all is well. I ensured air filter was clean, which it was. Any idea what would cause this? It has happened before also.
2555HST Low rpm
- Thread starter SC2555HST
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RNeumann
Elite Member
This is a shot in the dark as I have no idea on that model-
Some engines- especially computer controlled ones- won't allow the motor past a certain RPM if the PTO is engaged. If the PTO was engaged or the computer thinks it's engaged it may not allow higher RPMs. It would take a switch adjustment or replacement if the PTO wasn't engaged.
Some engines- especially computer controlled ones- won't allow the motor past a certain RPM if the PTO is engaged. If the PTO was engaged or the computer thinks it's engaged it may not allow higher RPMs. It would take a switch adjustment or replacement if the PTO wasn't engaged.
RNeumann
Elite Member
The other shot in the dark would be the TPS/APPS (something that tells the computer the throttle position). With zero info about Mahindra motors from the dealer I'd just check it with an ohm meter. You may see a flat or dead spot - especially as you tap/shake/move the sensor.
I'm still wondering how the PTO/engine speed ties together.
I'm still wondering how the PTO/engine speed ties together.
clevalley
Bronze Member
The only time I ever had this happen was below 20F degrees during startup and when the tractor overheated - the computer will not allow the engine RPM's to raise until it is safe to do so.
RNeumann
Elite Member
Hmmm same vain- computer getting false data that prevents going over a specified RPM.
mikeman1
Silver Member
Just got my mahindra 2555 hst today and the same thing happens. sometimes its fine, other times it won't go higher than 1600, then other times 1900...etc. w/o pto engaged, just driving around. will try it more this weekend and see if it only happens when it is warm, etc. and try to narrow down the problem.
Yeh, please let me know .
TSO
Elite Member
Possibly a "vapor lock" in your fuel system, could be getting air in the system somewhere. Open and close your fuel cap, and also Purge the air out of your fuel filter (most filter housings have 3 positions: Air, On, Off). This has happened to me before, my RPM's dropped, that fixed it.
Worth a shot...
Worth a shot...
mikeman1
Silver Member
Thanks for the info. I will try it this weekend. Dealer said to check the throttle cable as well. I am sure it will be an easy fix. Looking forward to a little seat time. Only had time to play with the levers, buttons and doodads yesterday.
jmh1783
Silver Member
Mine exhibited this behavior when I first got it. It showed up when it was hot. I'd shut it down and come back some time later and it wouldn't go to full throttle. My dealer did two things. First was the reflash. The second was to inject graphite into the throttle cable line. He said their are two sharp curves in the line. I've never actually looked at it. After that it has worked fine. I have had a couple of instances where it didn't quite get to full throttle and I moved it back and forth a couple of times to fix it. It may be the cable.
I'll look harder at the cable. It's doing it right now. Bush hogged for 30 mins, stopped PTO and did 5 mins of grappling, turned on PTO, attempted to take it up to PTO speed. Won't go past 1500. Stopped PTO, same thing, 1500 max. I've had the reflash. Gotta check the cable I guess next.
mikeman1
Silver Member
Well, I tried it today and it seemed fine. I put cable lube on it anyway on the left hand side where ti comes out by the engine and put it on the cable and on the housing that moves back and forth. used it all day turning it on and off just trying out everything, all switches, levers, mounting implements with hydraulics, taking the loader on and off, backhoe on and off, etc. no problems at all with the throttle. everything works fine. Nice power, used the 6ft rotary..real nice! The only thing I question is when the pto is engaged it clicks, right at then shaft, like a pawl is on. when I raise the rpm the clicking goes away. I remember someone else had the same issue on here. I will have to search for it. anyway, with the machine off i tried turning the spindle/shaft backward and it does not turn counterclockwise, but it turns clockwise and you can feel something like a pawl engage/disengage.
Everything else works real nice. What a nice machine.
Everything else works real nice. What a nice machine.
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