4120 engine injection pump spring update

[jtfx6552]

Dealer just took my 4120 in for an engine injection pump spring update.

Anyone else have this done? Any ideas what it was supposed to do?

My tractor, since it has been new, would change engine pitch, and start to put out some additional smoke. It does it intermittently. I figured it was an injection pump issue, but since I couldn't tell the dealer how to duplicate the symptoms, I was reluctant to pay to have them pick it up and try to figure out the problem.

When they called for this update, I was real happy, figuring this would cure the problem.

No luck, however, I think the new spring may have made the problem worse?

Any thoughts?

 

[tom30519]

Yes, earlier this spring, John Deere issued a recall for 4x20 engines in a certain range of serial numbers. My 4520 was done about a month or so ago. There's another thread here somewhere that talks about this, and gives the link to the John Deere notice.

Tom.

 

[jd110]

If the engine is running worse after the update, I would definitely call the dealer and have him recheck it. Part of the procedure in this repair involves "reclocking" the pumps. On almost all of the ones we have done, it results in a smoother running engine and less smoke. The method of reclocking the pumps has been revised since the update was released. Hopefully your dealer is using the latest and greatest procedure. The springs themselves won't affect the running of the engine unless the originals were broken. That was the reason for replacing the springs. They were having an unacceptable amount of them breaking.