John Deere 4024T

[Mmiller514]

Working on a Deere compact tractor model 4520 with 4024T engine. Replaced original 4024TLV02 with a 4024TF270 runs great but smokes terrible when starting clears up and runs great after 10seconds or so. Not a diesel mechanic but after looking at manual I’m trying to figure out if it could be the aneroid thermostat or injection rack magnet adjustment?
Any help would be appreciated!

 

[Diesel Dave]

Serial # of the 4024TF270 ?

 

[Mmiller514]

PE4024TO82671 came off a compressor unit I believe. Was told 1500hrs

 

[mg2361]

Welcome to HEF Mmiller514!

How about the machine's complete serial number?

It is not uncommon for the 4024's to smoke at start up, especially if there are some hours on the unit.

What color is the smoke? Is this something that recently started to happen, or has it been happening for a while? What was the ambient (outside) air temperature when starting? Glow plugs work?

If it runs great with no smoke after 10 seconds, then I think I wouldn't worry about it. You have no issue with the aneroid or magnet if it runs great with good power.

 

[Mmiller514]

Smoke is black. ambient temps 40- 70 degrees. Glow plugs working but has no effect. I know it sounds minor when I say it clears up so soon but it smokes bad enough initially you gotta run to get away from it! Lol Loads up so bad I doubt it would start if really cold. Once after sitting for several weeks it started much better. Made me wonder if an injector could be leaking off? RPM’s go up as it clears up then drop back to idle speed. Guessing that’s the extra fuel but why is it getting so much? Leaking injector or injectors or governor issue? Is there something that would allow the rack to open upon starting? Bought this tractor to resell but concerned this issue would scare a buyer away!

 

[mg2361]

Video the startup and post it. You have to use YouTube, then upload it to the thread.

Made me wonder if an injector could be leaking off?

Could be, but injectors are not sold separately. They are matched to the unit pump. However, they can be pop tested.

RPM’s go up as it clears up then drop back to idle speed.

This normal. The rack is at full fuel position when the fuel shutoff solenoid is turned on, then the rpm's ramp up at startup until there is enough engine speed to move the counterweights on the governor and bring the engine speed back to idle.

 

[Mmiller514]

I’ll attempt a video! Thanks for the input. I have seen injectors listed
individually in the parts catalog. These each have their own integrated pump. Looks like a bear to replace though!

 

[mg2361]

Looks like a bear to replace though!

It is not a DYI job unless you buy tooling. There are special tools to set those pumps and the settings are made in the thousands of an inch.

 

[Vetech63]

Looks like a bear to replace though!

Have this done by someone with experience on this engine. The special tooling alone to do this job is complicated to a novice. It would be well worth the cost, and you should get a warranty with the work.