Oil & Fuel Fuel Pump Timing Help??

[normde2001]

"I removed the injector pump and discovered a mangled, distorted and broken shim that varied in thickness from .014" to .020" from side to side."

So, according to my logic, somewhere in the middle of .014-.020 should work at least as good as before, with the original hard starting. I had 2 mottoes when I used to troubleshoot cash registers for a living. "The difficult we do immediately, the impossible takes a little longer", and "We strive for perfection, but settle for excellence"....Failure was not one of our options.

 

[gary1611]

I am a highly experieced auto tech little diesel experience but i must side with norm all that to thin oil in the crankcase must have done some lower end damsge rings in particular and this is the only thing i have not read you checked the tractor ran fine before the leak with the shimmied shim i dont think the shim is the problem (cause and effect)
the shim will effect duration the amount of time injector sprays but its not going to do alot with timing sure you can move it a few degrees either way. but your going through all that and i think you'll find its something else (rings). i'd do as norm said.
its easy enough to rule that out. My .02c

legall- this post is for enterainment purposes do not try this at home. I do not guarantee that any of the information contained in this post is correct, workable, or factual. I am not responsible for, nor do I assume any liability for, damages resulting from the use of any information

 

[gary1611]

Also the book for my yanmar shows the pump timing lobe as having a key way this would probly be unrelated to the hydro pump
bet one of those keys could be bent or wore wich would (posible dramticle) efect pump timing. i dont know how yours are.

legall- this post is for enterainment purposes do not try this at home. I do not guarantee that any of the information contained in this post is correct, workable, or factual. I am not responsible for, nor do I assume any liability for, damages resulting from the use of any information

 

[DavesTractor]

</font><font color="blue" class="small">( Verified hydraulic pump gear has no relation to cam, crankshaft or hydraulic pump timing.)</font>

Mark, I certainly respect your knowledge, but are you 110% sure the pump gear is irrelavent to the cam/crank/injection timing? I guess I need to pull the front off one of these engines or get out a manual to satisfy myself on this, but when you have checked everything twice you have to reconsider everything you "know". Keep us informed, thanks.

 

[California]

Mark,

Just thinking out loud. You have checked all the reasonable stuff so that leaves the 'impossible'.

Could there be a restriction downstream in the hydraulic system that causes a continual heavy load on the engine?

The other possibility with the past hard starting and mangled shims is that the previous owner knew he had a bad injector pump and put it back together anyway. It might be worth the trouble to take this pump to an injector shop for professional diagnosis.

Or since you have a similar engine on site swap pumps temporarily, and run each on the alternate tractor.

Good luck with this!

 

[mark777]

Dave,
I am fairly certain that the hydraulic pump and any relation to timing does not apply. Although it is gear driven, all it does is spin consistent with the RPM of the engine, as does the oil pump. Even with the tractor running poorly, the pump, loader and 3PH operates perfectly.

I realize it sounds absurd that I removed, repaired and replaced that pump and the tractor developed the symptoms it currently has, AND that they are somehow not related...but I have spent days checking all the possibilities including removal of crank pulley, timing cover and verifying that the crank-to-cam gears timing marks are properly aligned @ TDC on #1 cylinder. My confidence was high on making the repairs, but I am now certain of one thing...I am not 100% sure of anything (LOL).

Mark

 

[Jagmandave]

This may not apply, but................

I overhauled a 911 engine that had mechanical FI (many years ago), when I did the disassembly, I simply removed the pump assy intact and put it right back on when re- assembling - thinking that this way it should be fine. When restarted, the engine ran like poop.

Wound up taking it to a Bosch FI guy who had to rebuild the pump and reset the shims to get it to run right - I still don't understand why it changed to this day.

Your idea of swapping out the FI pump might have some real merit - at least to eliminate that variable. I also don't think it's a timing issue...........

 

[FL_Jerry]

Any updates Mark?

 

[mark777]

Hey Jerry,

Well...sort of. The number 1 barrel and plunger assembly in the pump is bad. Excessive wear on the guide, delivery valve and plunger. The 'book' says if one is bad replace all three. So my options are to replace the pump with used or rebuilt OR rebuild with new parts.

Rebuilding the pump is not that complicated and I think most any of us could do it, but I lack the bench test equipment to calibrate each plunger assembly to be consistent with the next. The pressures are dictated by shim thickness per each plunger...and all plungers have to equal and overall pressure........It looks like it would be a crap-shoot without the correct equipment to match, calibrate and test the assembled pump. I think I'll be going with the rebuilt...or a good used one if I can find one reasonably.

Not much of an update as it still isn't fixed, but thanks for asking.

Mark

 

[Cord]

I don't have any experience with the Yanmar pump, but I gave some knowledge about injection pumps and might be able to help you a bit.

Often the timing is taken off a plunger with a dial indicator. Yes, the setup is that tight. I don't know how the Yanmars are done. The timing can be set in a pretty good range. 15-18 degrees BTDC is common on my truck. I know some guys that run 21 degrees. Advancing the timing brings in more torque, better fuel economy but higher cylinder pressure and temps. A little is good, too much is bad. Retarded is safer but kills the power.