JD450 Injection Fuel Pump Static Timing ????????

[Mariner]

Hi guys,

Finally got around to taking the fuel pump off the machine and working on it. While I had the pump off I replaced the drive shaft as the old one was badly worn at the drive tang.

I replaced the pump and set the timing to what I think is around 5 degrees BTDC ?????

With the new parts installed and the timing in the correct position on the engine - the pin fully inserted in the flywheel hole, I rotated the fuel pump 2.5 divisions on the graduated scale on the mounting flange. Prior to moving the pump, the two lines inside the fuel pump timing window lined up. This being what I thought, was cylinder TDC, I rotated the pump to give what I thought was about 5 degrees before TDC (1 division = 2 degrees ??? ).

I started the engine and it fired up right away (after much messing with bleeding injectors etc.) and the exhaust was smokeless / clear !!!!!! I tried varying the rpm (no load) and found the engine responded very well to the throttle pposition movement and just a hint of very light blue smoke at high rpm.

After thinking about what I did, I am not sure the timing is right !. Should I have used the plastic window to set the timing ? Am I out to lunch with my reasoning - the manual doesn't tell me much ( maybe I have misread it ).

Could someone please advise if I have gone the wrong way with the pump adjustment. First indications show a great improvement in engine operation and response - could it be better or should it be better ???

It is -22C / --4F and any more work will have to wait until the temperature improves a bit outside

Thanks in advance for any help.

mariner

[Mariner]

Ok - I decided to go and re-read the section in the manual. This time I think I have it right

After checking the fuel pump timing marks are aligned internally, the pump is then tightened in that position. This is for the correct static timing.

The engine should then be run at 1400 RPM and the small window checked for automatic advance of pump - for the pumps fitted with the Automatic advance - which is all for the John Deere application as far as I can tell. At 1400 rpm the advance should be 5 degrees - this is where I think I got the value from.

So, to get it right I need to bar the engine over to TDC and pin in, then loosen and rotate the fuel pump back until the two lines (internal) line up and then lock the pump flange. Run the engine at this setting to check the operation. The auto advance mechanism should then operate properly and compensate for the speed part. There is more detail, but of course I failed to remember this part. Just put it down to a "senior moment". I am pretty close as it stands and the final adjustment can wait until the weather warms up a bit. I also need to install a tacho as I don't have one - will look at the "Tiny Tach" as it gets great ratings and is reasonably priced - check out this link.

http://www.tinytach.com/tinytach/diesel.php

Cheers

mariner

[Tigerhaze]

This thread may help you concerning adjustment, especially the last post by Jdemaris:

http://www.jdcrawlers.com/messageboard/ ... light=lazy

Also when you say "manual", i assume that you are referring to the service manual for the 450?

FYI, there is another manual for JD injection pumps that has a lot of spec and supplemental information that may be useful to you- it is SM-2045 (Testing and Servicing Fuel Injection Pumps and Nozzles). It is available from the Deere manuals website; at one point there was a PDF of it on a file sharing site but not sure where that is anymore.

Things such as theory of operation, bench testing procedures, etc. are included in that manual. It also includes the specified advance at various RPMs for each model of JD injection pump.

Hope this helps.

[jdemaris]

The engine should then be run at 1400 RPM and the small window checked for automatic advance of pump - for the pumps fitted with the Automatic advance - which is all for the John Deere application as far as I can tell. At 1400 rpm the advance should be 5 degrees - this is where I think I got the value from.

Older pumps like the DBGFC431-2DH series work like this:
The timing advances 2 degrees by 1200 RPM, 10 degrees by 2000 RPM, and 12 degrees at 2500 RPM.

Newer pumps e.g. the JDB435AL2707 work like this:
The timing advances 2 degrees by 1000 RPM, 10 degrees by 1600 RPM, and 15 degrees at 2300 RPM.

Those figures are in engine degrees and engine RPMs. Since the pump runs at half engine speed - advance and RPMs are cut in half. So - 1 degree at 600 RPM AT the pump equals 2 degrees at 1200 RPM AT the engine.

Nice thing about Deere is they ordered their pumps with the optional adjuster screw. Many other companies did not.

[MattE]

I have the pump manual on pdf if you need it let me know.