Its a 6 cyl JD engine in a 644C Loader. When I start it up it revs up to a couple thousand RPMs then comes back to normal idle. every startup every time. Looking for some ideas, I was thinking injector tips? return lines? As its getting colder here I need to get this fixed as thee ol' diesels don't really like jumping straight out of bed
What engine? JD makes ALOT of 6 cyl. engines..Can you snap a pic of the injection pump? Are you holding the throttle/pedal to the floor when starting? or just turning the key? Depending on what fuel system is on that engine, depends on how we diagnose it. Might have a sticking throttle? can you get someone to watch the injection pump throttle lever when you start it? If its a Bosch "inline" pump, they have a "start spring" inside the governor that pulls the rack to "wfo" for starting and a magnet, either inside the gov. or under the "rack cap" on the front of the injection pump, to hold the rack to WFO until pump/engine rpm releases it, by centrifigul force. You can "bypass" the magnet by pulling the manual shut off cable SLIGHTLY to get it off the magnet, then try to start it..Hope that helps..TPG
The governors on the older Deere motors start up at full throttle and as the weights spin up they bring the throttle back down to idle. They make a lot of smoke and basically scare the heck out of people who don't know that is a normal thing for those engines.
Ok here are some pictures of the unit. where would this spring/magnet be located?
I just push the start button. no throttle.
That JD 466 engine was used in their ag tractors from the same era and they rev up like that from the factory without any consequences.
I think the others are right..I cant read the nameplate clear enough to look-up the parts list.9 400 230 or231 ??? You could check the front of the pump for the magnet in the rack cap..the spring IS INSIDE THE GOVERNOR..and you dont want to mess with it..its working, obviously..
It is 9 400 230 032 When its -20 out the last thing I want to do is give this thing wide open throttle at start-up...there has got to be a way to adjust or stop this.
I looked up the parts list and there is just a spring showing.. You can try to "help the rev" by pulling the shut down cable slightly before starting. Only other thing to do is have A QUALIFIED FUEL INJECTION PERSON remove the governor and install a weaker start spring. I dont recommend it tho.. JUST TRY to work with the shut off cable FIRST.. good luck..TPG
It looks like from your pics. your useing the throttle as the shut down lever??? [ 2 cables ] and moving the throttle past low idle to shut down?? On the back side of the pump, opposite side of the throttle, is an actual shut off lever, towards the bottom. it pulls back for shut down. Leave the engine throttle in the low idle position...reach around the pump and pull the lever back alittle and have someone crank the engine while holding the shut off lever back slightly. IF THIS HELPS, just rig up a cable from the lever to the cab..worst comes to worst just use a piece of string, as the shut off lever should be "spring loaded" to the "run" position..
Alaskaforby4 That's how they start. I had one in a 690b excavator. When it was cold out it would smoke, pop, fart and grumble to high RPMS on start up. Obviously your loader has started this way for years with no ill effects. Is it from Alaska?
One is the foot throttle and one is a manual hand throttle. Thanks for the idea. I'll give it a shot
Yes it is an old state loader that has been kept indoors, its having a rude awaking being outside for start ups
Yep, that's just how they start. The governor goes to full throttle on start up.