Tractor ECU solinoid throttle control bypass?

[Dasa]

Hi sorry this is not related to my Nissan but hopefully you are still happy to help.

We have a John Deere 6320 SE which is a fairly simple pre commonrail engine but the throttle control is electric and has been a intermittent problem for ~7000 Hours for numerous reasons Wiring\ECU and it is looking like we are back to replacing the ECU again.

Symptom is the engine flutters badly when trying to maintain a RPM above idle but it accelerates ok if you keep moving the throttle up at a steady rate till you stop moving the throttle or hit max then it starts to flutter.

Is there any way to replace the two wire solenoid with a manual throttle or at least bypass the ECU with a aftermarket controller for the solenoid?

Thanks



On a side note Recently my 94 TD42 was turning over a long time when starting especially when warm thankfully it was just the starter had a seized bearing and two of the 4 brushes were warn away making the cranking speed a bit low.
I didn't expect the dam thing to be harder to get out than our 2010 Hilux starter but there is not a lot of room around those bolts on the old td42 is there.