5085E ENGINE RPM IN E-PTO

[Brown Dog]

I can’t figure out how to get engine to rev past the 1700rpm while in EPTO.

I know it has electric throttle as compared to my 5093E & 5101E cable operated.

I simply unhooked the cable above Left Rear axle to the injector pump on them to let engine rev WOT.

I unhooked the black sensor on rear & engine will rev past 1700rpm in EPTO BUT the PTO rpm in dash doesn’t read.

I know the haters is going to bash me. I’m prepared

I only run my two older tractors this way to get a little more blade tip speed on a slow turning Brush Cutter & it cuts MUCH Smoother without any problems thru the years.

 

[hosspuller]

You can't do it. Deere has put a rev limit to Avoid over speeding a 540 rpm implement. By disabling the sensor, you 're essentially in run-away condition. The dash display obviously needs the sensor.

 

[oosik]

You want the engine to rev past 1700. Take it out of EPTO. That's all EPTO does - limits max engine rpm.

 

[ptsg]

You want the engine to rev past 1700. Take it out of EPTO. That's all EPTO does - limits max engine rpm.

The OP wants to slightly over speed the PTO so he can get a better cutting action and finish on the 3pt mower.

 

[LouNY]

If you know a JD mechanic that is good with the new software he might be able to defeat that provision.

 

[Brown Dog]

It can be done I’m sure. I just hadn’t found out How.

I rewired one of the Two rear sensors on a 4720 to achieve this & it worked great.

 

[CobyRupert]

What would happen if instead of disconnecting sensor that tells brains the rpms, and limits fuel so that you don’t overspend when pto is on, you disconnect sensor that lets brain know the pto is on? It might not limit rpms if it doesn’t think pto is on. Shot in the dark.

 

[Brown Dog]

That may work BUT your still not going to have the PTO rpm reading in the dash .... I don’t think ?

I know what engine rpm to run at : this is what I have to do with my 5093E & 5101E because the dash does not show PTO rpm. reading.

I’d like to have the PTO rpm reading in the dash as it does now, if possible.

 

[CobyRupert]

That may work BUT your still not going to have the PTO rpm reading in the dash .... I don’t think ?

I know what engine rpm to run at : this is what I have to do with my 5093E & 5101E because the dash does not show PTO rpm. reading.

I’d like to have the PTO rpm reading in the dash as it does now, if possible.

That sounds like a software over-ride might be necessary. I'm sure John Deere will let you access software to change it, I mean you own the tractor, it's yours to do what you want to, right? (<---sarcasm, see related stories, lawsuits, etc..)

Without getting into the processor you can only fake out the external inputs or outputs.
Taking a guess, it sounds like related inputs/outputs to control system are:

Inputs:
- ePTO mode selected
- PTO "on" switch
- PTO rpm sensor/tach
- Engine rpm tachometer

Outputs are:
- To fuel pump
- Others?

I assume a processor uses inputs to determine logic/conditions to control fuel pump output so that a maximum pto rpm limit isn't exceeded (as measured as an input). Or did you say wire runs directly from pto rpm sensor to fuel pump? Can you still operate tractor if wire to fuel pup is disconnected?

So here's another shot in the dark: Is there a way to mechanically put tractor in ePTO mode, but not let control system know it is? Thus the rpm limiting control logic (processor) interlock doesn't kick in?

 

[Brown Dog]

I talked to a JD guru tech & he said it can’t be done thru the programming.

He said me unplugging the black sensor out back is the only way it can be achieved.

I guess I’ll just use my 93E & 101E for mowing.