L275, D1302-A engine timing problem

[LeadHead]

Long story, bought this L275 some time ago with a hole in the block. It ran fine on 2 cylinders and we drove it up on the trailer, then drove it into the shed after getting it home. A year ago I finally found a donor tractor with a good block, and with a buddy helping me we split the tractors and swapped engines. After reassembling it, I took it to a local tractor mechanic and with sort of a "barter" arrangement he re-ringed the engine and replaced valves, fuel injectors, etc...
The tractor now runs but is very hard to start, but once started it runs smoothly while blowing a lot of smoke. I thought it was blue, but it smells like unburned fuel. Also, in top gear the tractor will hardly pull itself along and in some of the lower gears it doesn't feel like it is running at peak power, either.
Tonight I pulled #1 injector line to see if the injector pump is timed properly (we used the injector pump from the blown engine on the donor engine which was missing the pump). When I turn the crank until I first see movement in the fuel level, there is no timing mark visible in the flywheel inspection window whatsoever. Thinking maybe some idiot had removed the flywheel and not reinstalled it correctly, I then pulled the valve cover and turned the engine over until #1 cylinder was at TDC, and looking in the inspection window it was practically dead-on the 1-TDC mark. Once proper TDC was determined to be calibrated with the flywheel, I then rotated the crank until the fuel level started to rise in the injector pump and it appears that it's not beginning the fueling process until about 80 degrees AFTER TDC.
I distinctly remember when my buddy and I reinstalled the front of the engine we made sure that the timing marks on all the gears had the proper number of dots lined up with the crank, but is it possible that the injector pump gear is 180 degrees off? If so, does that number somehow correspond with the 80 degree ATDC timing issue? Common sense would tell me that since it should normally start fueling 20-25 degrees BTDC, then if it were out of time 180 degrees it should start fueling 155-160 detrees ATDC, not the approximate 80 degrees ATDC it appears to currently exhibit. On the other hand, I'm not a real mechanic and some of these things confuse me.
Any help would greatly be appreciated!

 

[LeadHead]

I need to make a correction. A friend told me to determine TDC by watching the valves, i.e. the exhaust should be just starting to close while the intake is starting to open, rather than then turning the crank another 360 degrees to be at TDC on compression stroke. So my previous comments are inaccurate in that it now sounds like the injector pump is starting to pump fuel at 280 degrees BTDC instead of the 80 degrees ATDC as I originally thought. Hope this helps someone to understand my problem.

 

[Stumpy]

Actually that's more confusing, 280 degrees before TDC puts injection back in the intake stroke. It shouldn't run at all like that and if it did it would knock like crazy and probably punch holes in the pistons. If you lined up the timing gears properly then it should be impossible for the timing to be that far out. It is possible to put the flywheel on so that the timing marks aren't accurate but with no other ill effects (at least on my machine it is) I don't think you're measuring TDC properly. It sounds like the valves are in time at least, most diesels are inference engines so if the valves were out of time they'd crash into the pistons.

It's not easy on a indirect injection diesel to see when the piston is at TDC which means you usually have to rely on the flywheel marks. You might try removing both the injector and glow plug for cyl 1 and shining a flash light through the glow plug hole while looking in the injector hole. Have someone turn the engine by hand while you're doing this (remove all the glow plugs first). If you're lucky you'll see the piston as it hits TDC. If that fails a sure fire way is to drop the oil pan and look up but hopefully it won't come to that.

I had one other idea.

The only way you may have messed up timing gears it if you rotated the crank before all the gears were installed. To have proper timing they must all line up on the idler gear at the same time like in the picture above. Once the engine starts rotating they won't all line up again for a few thousand rotations or so but as long as they all lined up when assembled the engine will be in time.

 

[LeadHead]

I would be willing to put money on the fact we had all the dots lined up on the gears, but that was last summer (it's been sitting since then). Is it possible for the dots to be lined up but somehow still be out of phase?

 

[Stumpy]

Not that I understand. That's why they did it that way, so as long as they all aligned when installed everything was guaranteed in time. The fuel cam gear is keyed to the fuel cam and I can't think of anything that would throw the timing that far out inside the injection pump.

According to my book correct timing for your model is 25° BTDC. When the cylinder 1 injector fires "|F1" should appear in the timing window followed 25° by "|TD1"

 

[LeadHead]

Yep, 25* BTDC is what my books say, too. I just have no idea how it could be out of time so far unless the pump gear is way off. Sure wish there was a way to check those marks on the gears without pulling the front of the engine apart.

 

[Retlaw66]

Minor timing changes are made with shims under the injection pump.
I rebuilt my L275 back in 2008. After milling the deck, the shims needed to be changed to get it properly timed.

The spec is for before TDC of the COMPRESSION stroke. NOT TDC when the intake valve is starting to open.

For my rebuild, I used the 'Kubota Workshop Manual, 03 series diesel engine' that I downloaded off the net.
Injection timing is covered on page S-105.

 

[LeadHead]

So, I pulled the front gear case cover and the engine is way out of time. The cam was 1 tooth off and the injector pump was 165-170 degrees off. I have no idea what happened. Waiting for the new gasket and crank seal to arrive on Tuesday so I can put it all back together.
Still wondering how this happened.

 

[Apogee]

You were busy focusing on the cute 25 year old next door sunbathing in her bikini...

Or, too many beers while re-assembling.

Heck, it happens to all of us at one time or another. Just glad you found it.

Good catch!

;-)

 

[LeadHead]

The problem with that theory is that we have no neighbors that close, and I don't drink. Any other ideas? Maybe simple ineptness?

 

[LeadHead]

Update:
My replacement gasket finally arrived and this week I got it all put back together. After bleeding the fuel lines and glow-plugging it, she fired right up and runs like she should! Sure is nice to have it running properly, and I bush-hogged our pasture yesterday. The engine pulls like a champ through all 8 gears and idles nice and smooth. It still seems a bit difficult to start when cold, even when the outdoor temperature is in the 60's. When it does start (cold), it sounds like it's running on only 2 cylinders for a short time, so there may be one dead glow plug.
Sure is a relief to have it running right again!

 

[Apogee]

Nice work!!!!

Glad she's fixed.

Have fun,

Steve

 

[Retlaw66]

It still seems a bit difficult to start when cold, even when the outdoor temperature is in the 60's.

My L275 likes a 30 second glow-plug warm-up even in the summer. My newer B2100 is good to go after 15 seconds. I'm curious if there is a difference between the two systems.

 

[LeadHead]

Yep, 30 seconds is about what mine wants, even in 70 degree weather. Seems a bit long to me, but maybe it's just the nature of the beast. I'm really considering a block heater for the coming winter since it'll probably be my main snow-moving machine, unless we get some really heavy stuff which requires a front loader for removal, in which case the WD45 comes out of the shed for duty.