Oil & Fuel Fuel Pump Timing Help??

jbitting · Apr 1, 2006

Mark,

Wonder if an intake valve not opening properly would cause this... of course, if that's the case, it would probably indicate more serious problems lower in the engine. /forums/images/graemlins/frown.gif

just a thought...

Once you figure this one out, be sure to let us know...
We're all quite curious about this one.

Jake

YanmarFever · Apr 2, 2006

Mark, I have an extra 1610 hyd pump on a parts engine.
We could send it to you so you could try it out and see if thats your problem. your only cost is shipping between us if it doesnt work.
Ernies imports

DavesTractor · Apr 2, 2006

Mark,

Does the hydraulic pump gear act as an idler gear, so to speak, for other gears that could run the injection pump? When you had a hard time getting the gear back in and had to move the fan a little, you could have something off by a tooth. We put a Branson together once with the gears off by a tooth or so and it caused me no end of grief until I pulled the front off the engine and put everything in exactly right. Then the smoke went away and the power back up to normal.

Maybe Aaron or Ernie could comment. Is my scenario possible? Essentially the crank got turned a little but the injection pump didn't because the gear was out? I know it works that way on some engines, not sure on the Yanmar.

mark777 · Apr 2, 2006

HGM ,
Fuel is fresh and I have filled three other tractors with same..everything's normal.

Jake,
The intake is air and seal-only on a diesel as the injectors spray into cylinders...if it were gas that would be one of my first guesses though.

Ernie,
Thanks for the gracious offer, but the hydraulic pump is working perfectly...I was hoping for a connection about disturbing the fuel injection pump when I removed and replaced the hyd. pump, but I don't see how they are related (timing wise anyway).

Dave,
The majority of Yanmar dealers and suppliers, including Aaron @ Hoye, state the timing of the fuel injection cannot accidentally be changed...you have to physically remove or replace shims and/or take the injection pump apart. But your scenario is what my primary concern was at the beginning of my post.

Thanks everyone.

My intentions were to remove the timing cover...because if I don't I'll always wonder. If everything is aligned on the marks, I will remove the head and determine the internal damage to head and block (rings, pistons, walls etc.) I ran out of time this weekend completing other projects, but it's off the back burner and I'll start on it this week.

Mark

bruce1966us · Apr 2, 2006

If memory serves me correctly, the valve camshaft and injector camshaft run directly off the crankshaft. The hydraulic gear can run at any position. Does the engine run smoothly at any RPM?

bruce1966us · Apr 2, 2006

Mark, you won't find the timing marks aligned. When the engine is initialed "timed' the marks align. After that , the engine must turn xxx amount of revolutions before the marks align again. Try it and you will see!!

mark777 · Apr 3, 2006

LOL, yeah..I meant rotate the crankshaft until the marks align.

greatrandini · Apr 3, 2006

I still say you have air in your fuel lines! Simple fix!
Later dude!

mark777 · Apr 3, 2006

Great,

3 Weeks ago, I replaced fuel bowl, O ring and retainer nut, jar and valve assembly...all new urethane fuel lines from the tank, from the fuel filter, to the thermalstart and bleed completely. I then switched all the metal lines, fuel bowl assembly, urethane lines and injectors from one 3T75U engine to another, bleed and ran the other tractor...it runs perfect and not one hiccup. Anything fuel or air related has been replaced with new...even hose clamps OR swapped with known components that check out O.K with another good running tractor.

I was then, where you are now...hoping for and eliminating all the simple fixes. And what you stated in your post, it would be the first thing I would recommend to another member to look for. I do appreciate your, and everyone's suggestions, no matter how simple or far fetched, as I did NOT want to tear an engine apart that show no signs of blow-by but I am out of ideas.

Mark

greatrandini · Apr 3, 2006

Well maybe u r off the mark? When u tear it down keep us posted. I assume u bled the fuel lines all the way to the injector pump? U can crack the nut on the flare fitting at the injector line.(bleed from there) I am sorry if u know all this already! I just hope to save u some work.

normde2001 · Apr 4, 2006

"U can crack the nut on the flare fitting at the injector line."

You accomplish nothing by bleeding the injector lines, just make a big mess. If the pump is properly bled, it will self-prime and force any air out of the lines with fuel.

Mickey_Fx · Apr 4, 2006

Mark, since I owe you I'd sure like to help but have no experience in this area.

I'm with you if it was running OK prior to pulling the hyd pump it shouldn't be a fuel/injection problem.

Will be interested in what you find after pulling the front cover off.

greatrandini · Apr 4, 2006

Our experiences have caused us to have different conclusions!
I once could not get my unit to run properly until I did the before mentioned. You are speaking in absolutes! I learned how to do this trick from HOYE's web site. I don't mind being told that I am not correct unless I am!

Normmm · Apr 4, 2006

Could there be a problem with the governor or linkage. I had a problem with an old gas tractor with loss of power that turned out to be a linkage problem caused when I worked on the water pump. How doews the governor work on this tractor and could it cause this problem.

mark777 · Apr 4, 2006

Mickey,

I pulled the front cover off this morning and rotated cam and crank gears...marks line up perfectly. The bob-weights for the governor operate fine and everything seems to be in good shape. Also pulled the cam stub for the fuel injection timing and mic'd the lobes...they are all within .020" with no mushroom'ing....SO

I keep a tidy shop and spent the last few days looking for my old reliable diesel compression tester. I think it grew legs (stolen) and walked out as it's something I don't loan out. Now Pop's is bringing his over tomorrow, so I'll be able to do a leak down and compression test in the PM.

With the absence of blow-by I am leaning towards cracked seat or valve...(hopefully). I let you know.

BTW, you don't owe me anything /forums/images/graemlins/smile.gif.

Mark

normde2001 · Apr 4, 2006

...whatever you say, Great /forums/images/graemlins/wink.gif.....have a good'n.

HoyeTractor · Apr 4, 2006

</font><font color="blue" class="small">( I learned how to do this trick from HOYE's web site )</font>

That is really meant for starting a tractor that has run out of fuel. Once it gets started, it should bleed the air out itself and you should not need to mess with them--- in a perfect world /forums/images/graemlins/smile.gif.

Aaron
Parts@HoyeTractor.com
(940)592-0181

bruce1966us · Apr 4, 2006

Mark, does the engine run correctly at any given rpm range?

mark777 · Apr 4, 2006

Bruce,

It did run fine before and during the white smoke mixture of hydraulic oil, fuel etc. After I installed the new hyd. pump seal the smoke cleared up nearly instantly. It then ran fine for 5-10 minutes under no load circumstances. During the 5-10 minute duration it would suddenly drop from 2350 to 1750 rpm...and cough, sputter and produce un-burnt exhaust (the eye burning kind), and nobody near the tractor. After several attempts to just let the tractor run, on occasion the rpm variation was so drastic it would stall. It would restart immediately and recycle the 5-10 minute thing all over again.

My last test, by dropping the box blade and attempting to bring it up to temp...the power was way off, maybe even as much as half. The blade, once engaged would (did) stall the engine. Nothing has been consistent with the tractor since I reinstalled the hydraulic pump, except the eye burning exhaust and a little hard to start, as it's done that for the last 30hours (2 years) as I seldom use the tractor. It is my tractor and not for sale like my others. It's not the first Yanmar engine I've been into...but the problems and my trouble shooting are way off the mark on this one.

Mark

bruce1966us · Apr 4, 2006

When you have the head off make sure you don't have a bent rod. A little hydro fluid could have got on top of the piston and caused this. I have seen it before. It would blow unburned diesel in that cylinder since the piston would not rise far enough to ignite it.