I got a 2017 John deere 35G and recently when I'm running the machine it won't go to full throttle. I keep it on eco mode but now I run it on pwr mode full throttle to get the speed I'm usually at. When digging it'll randomly bump up the throttle and it'll go to full operating RPM. Could this be the stepping motor or any other thought? Little side note I had it on a job with some shady guys for a while and I was taking the main fuse out to kill the system so they can't start it. I've done it tons of time but that may have nothing to do with it. Power seems the same but it sounds like it bogs down a little more than usual sometimes now maybe but hard to say for sure
Start with the basics. Fuel strainers and filters and then air filters.
Yeah going to do a full service on it but it seems like it more the stepping motor can that cause those issues? It's not like the engine is losing rpms its like someone is turning the throttle dial down
Does that that throttle motor connect to the fuel pump lever with a linkage or a cable? You can make a match mark somewhere and compare positions when working right and not working right. I don’t know what diagnostics are in that machine. Now days you can read the throttle position from the monitor panel.
The engine bay is fairly small is tough to work in without tilting the entire cab which I may end up doing but it looks like the linkage is all electronic and concealed within the housing so unfortunately there's no physical linkage I can check I thought about that too. I tried everything on the screen there seems to be nothing on there hardly. I wonder if I need to recalibrate the stepping motor?
Is the auto idle on?
What he said^^^^.
Please provide a serial number when posting. Plugged filters can lower engine rpm. Does the ECO change to PWR in the monitor when you select it?
Go in to the Display service meny and check the Trouble code record. If nothing there go the Monitoring and check the rpm meter to see if it acts strange. To open the Display service meny: Press the meny/back button with the ignition off and turn the ignition on while pressing the meny button.
Auto idle is off checked that and eco and pwr mode do work I always run it on eco like 3/4 throttle now I run full in pwr mode and it's about the same as is used to be. Then I'll be digging and it'll randomly go back to full throttle like it should then a minute later jump back down it's like someone is turning the dial.
Okay that may help actually I'll try that tomorrow or next day when I go to pick it up from the job I'll check back in
Access the service mode in the monitor. The 4 buttons across the bottom of the screen, press and hold the button on the left (the one with the double arrows pointing up), then key on or start machine. Release the button. Scroll to and highlight monitoring, press select (button on the far right). Scroll to and highlight switch, press select, then to speed dial, press select. What are you low idle and fast idle voltage readings? Then back to Engine Controller, press select. What are the actual low and high engine speeds in PWR mode? Then back up and go to Troubleshoot. Enter that sub menu and find Trouble Code Record. Any codes listed?
Okay I will definitely check that I am home today tomorrow or next day when I get machine I'll try it I would've never guess to do that awesome advice
Finally picked up machine so have an update. I just did filters and nothing changed so wasn't that. Here's some stats Engine speed Control dial voltage at idle: .61V, WOT 3.35V Engine rpm at idle: 1300, WOT PWR mode: 2264 Battery voltage idle or wise open is 14.2-14.4 The last trouble code read at 1300 hours has almost 1900 now didn't own it then but it says "ENG:00436-04". I never had an issue with the machine ran great but that's everything I could find in the monitor hope that helps somewhat thanks guys
Correct engine speed control dial voltage in PWR mode is 0,6+/-0,1v at idle, WOT 4,0+/-0,1v,so something is wrong. If you are sure there is no more fault codes my first guess is problem in the harness. ENG:00436-04 is Speed sensor error. There is one thing I need to ask. Factory setting of ECO mode is 78% of PWR rpm, that means 1895 rpm and you normaly run the throttle at 3/4. That means less than 1895 rpm. Now you work at WOT PWR mode 2264 rpm to get the same speed as before. Do you normally work with the A/C off but now it is on? The only thing that externally changes the pump torque is the A/C mode. If it was my machine i would change the ECO mode setting to 100% to see what happens.
Yeah the first trouble code was at 1300 hours I checked multiple times nothing else. No AC I should've noted actually that it's an open cap machine so nothing there like ac heat radio obviously. I was playing around with the setting today they had eco in like 74 or 75% but I like that idea I'll try putting it on 100% and try that. If that voltage is wrong makes me wonder what you said about the harness the last job had a lot or mice around wonder if they chewed a wire. Only issue is how do I ever find it.... as you know finding electrical problems can be extremely difficult
Also forgot the mention that voltage I mentioned may not have been in PWR mode but on eco I can't remember I'll check again tomorrow
Check the voltage in PWR mode to be sure. On our Volkswagen cars the only way I have found to know if a fault code is active is to clear it to see if it comes back. I do not know if it is the same on the Hitachi/Deere/Airman but I would clear the fault code if it was my machine.
Okay will do maybe the fault list is filled up to much? I don't know but there's 5 pages of all the same things periodically it looked like I'll clear it tomorrow run it for a day or two and see what happens check back in with voltage reading as well thanks!
Today I checked again, voltage didn't change in eco or power mode. Also turned eco to 100% didn't change anything so it's definitely not getting enough voltage if you're saying it should be 4V. So possibly harness issues? Or could it be stepping motor? I just hate to replace parts without knowing especially with prices these days
Probably just a bad speed dial.
Yeah could be ill probably change that and see what happens maybe I can bypass it somehow to go to full voltage to rule out the stepping motor?