John Deere 4024HF285 conversion for CT322

[Bhawk44]

I have a 2006 John Deere CT322 that had a 4024T engine that I replaced with a 4024HF285. The 4024T is a fully mechanically governed engine and the 4024HF285 has an ECU. It was designed to run in a generac generator at a set RPM. I was able to wire up a throttle emulator (potentiometer) that gives me throttle control from idle to 2000 RPM, but cannot figure out how to make it run up to 2800 RPM. The wiring diagrams from Deere for this engine show different throttle control combinations including a main analog throttle emulator and a multi-state throttle that uses different resistances to control the rpm. The diagrams do not specify what the resistance values are so I have tried to use a second potentiometer in the multi-state range control circuit to see if I could find the right resistance to make the primary throttle emulator give me 2800RPM but was unsuccessful. I’m thinking that the ECU software may need to be reprogrammed for a higher RPM value but have no idea how or if this can be done. Do any of you have experience with these ECU’s?

 

[mg2361]

Welcome to HEF Bhawk44!

What is the complete engine serial number of the HF285?

More than likely, since this is a generator programmed engine, it will have pre-programmed limits. With a serial number, I can look at the trim page to see what range is available, if any.

 

[Bhawk44]

Any info appreciated, thanks!

 

[Bhawk44]

This is the ECU:

 

[mg2361]

Trim page will not allow any engine rpm changes.

 

[Bhawk44]

Is there any way to reprogram ECU or would I have to get a different ECU to make this engine throttle to 2800RPM? Also, do you have a link to the S/N trim page you reference? Thanks

 

[mg2361]

do you have a link to the S/N trim page you reference?

There is no public link. It is dealer eyes only.

Is there any way to reprogram ECU or would I have to get a different ECU to make this engine throttle to 2800RPM?

It could be done. The issue is Deere frowns on having more than one ECU out there being used for one machine serial number. You will have to see if your local Deere dealer will be willing to program it for a machine/engine that has full throttle control.