2610D Injector pump timing

[rock2610D]

Well, I took Mark's advise and called a diesel specilist and told him my "Story". He said immediately that if its a Japaneese tractor made to run in Japan that Japan's diesel fuel is MUCH better than ours. And a tractor could be hard to start in the US Expecially at high elevation due to poor diesel. He suggested a double dose of Cetane improover and Premium Diesel if possible.

I was also told the it is very possible that the compression ratio for Japanese tractors is lower than ones made for U.S. diesel fuel. He said he would not be supprised to find 18:1 or even a little lower on tractors made for Japaneese Markets due to their GOOD diesel. That combined with high elevations and poor diesel WILL make a tractor hard to start in cold temps.

Here is a quote from an artical I read.

"Aromatic hydrocarbons have poor self-ignition qualities, so that diesel fuels containing a high fraction of aromatics tend to have low cetane numbers. Typical cetane values for straight run diesel are in the range of 50-55; those for highly aromatic diesel fuels are typically 40 to 45, and may be even lower. This produces more difficulty in cold starting, and increased combustion noise, HC, and NOx due to the increased ignition delay."

U.S. Diesel is highly aromatic. IE 40 to 45 Cetane
Japanese is Low aromatic IE 50 to 55 Cetain


Going to try to increase my Cetane #s and see what happens.

 

[tmoritz]

For what it's worth re. the diesel issue. I know that German car makers (especially VW) have been lobbying for significantly better quality diesel in the US for years. In light of that, that part of the comment by your mechanic makes sense.

 

[Mickey_Fx]

Compression ratio of a diesel depends a lot on combustion chanber design. There are 5 and maybe more with recent designs, and each offer its own starting and operating characteristics. The Perkins I had in my MF 165 had a compression ratio of 15:1 and no glowplugs. Started easily in our winter time temps about mid-30's. Don't know what combustion chamber design Yanmar uses.

 

[mark777]

Hey Rock,

This is probably just too simple but I thought I'd mention it anyway...

Have you removed the intake tube (from the air cleaner) and tried starting your tractor since the new improvements? Was just thinking that the slightest restriction of air could be adding to cold start issues.

Also, I don't recall if you use your thermostart for prestarting the engine? As the design is specifically for pre-heating the enclosed atmosphere contained in the intake...I would think this would help significantly...NO?

 

[rock2610D]

Yes, I did try removing the intake air hose, it did not help. But now I have a turbo on it and am anxious to see if the turbine (exhaust) side of the turbo will help keep some heat in cylinders.

Yes, I do use a new thermostart. I do not however use the decompression anymore because I get a better start if I crank the engine with the fuel OFF. I believe the COLD fuel may hinder starting and so I crank with no fuel for about 10 to 15 seconds and then pull throttle lever.

I am going to wire the thermostart to a toggle switch so I can keep it on while cranking. My owner's manual reads that I should engage the thermostart system for a while AFTER engine has fired to help with cold weather starting. I figure if it is ok after engine is started it should not hurt while cranking???

If all this fails I am going to double check the valves and test actual compression.

I ordered a service manual for a 2610D and recieved a service manual for a 336D could someone tell me if the compression should be the same for a US model 336D and a Jap model 2610D Engine 3T80D?? If not can anyone tell me what the factory compression should be? I can correct for elevation after I have correct numbers.

Just a side note here but last March when it was below 30 deg F. I took my wifes hair drier out to a cold tractor and pushed the Hair Drier outlet into the intake side of the air filter and turned it on. Let it run for about 30 seconds and cranked tractor without thermostart or decompression lever and it started immediately!!! I mean maybe only 1 rev of the motor a POW it was started

 

[MJPetersen]

Just a side note here but last March when it was below 30 deg F. I took my wifes hair drier out to a cold tractor and pushed the Hair Drier outlet into the intake side of the air filter and turned it on. Let it run for about 30 seconds and cranked tractor without thermostart or decompression lever and it started immediately!!! I mean maybe only 1 rev of the motor a POW it was started

Rock I am really interested in your turbo addition. When you get a chance some more comment and a pic or two would be nice. In the future maybe some other info like response and power comments. Especially when you get the size that you need. I understand that currently the turbo is too large and spends alot of time in surge, right?

About the hair dryer -- I had an old Ford transit van that had a 2.5 liter normally aspirated diesel. When it got very cold (below 0 F to -30 F) I had to regularly use the hair dryer or heat gun to give the thing a breath of warm air and it rarely did not do the trick in starting. Anything that will warm the intake air will help.

Mike

 

[Mech]

I had a Yanmar 1610D that I posted about here. It had low compression and wouldn't start w/o the Thermastart or cranking for 20+ seconds. I have bought a new JD 790 which also has a Yanmar engine and it has to crank for 10+ seconds to start at temperatures below about 80 degrees. I live at 8600ft. It starts instantly if the engine has been run (even a few seconds), if I use the intake heat (no thermastart, only intake heat on this tractor), or if I have the block heater plugged in. Throttle position or a diesel additive have not made a difference. At this point I just use the intake heat if it is below 80, which except for some afternoons in June, July and August it always is.

 

[rock2610D]

Thanks, Mech! I read your post but I could not tell if you were ever SURE that the tractor actually had compression problems or if it was the altitude.

I have used a hair drier to warm intake air and help pressurize the intake and tractor fired immediately.

Compression testing is a waste of time and $$$ unless I can determine what my compressions is supposed to be.

You like most everyone I have spoken with have issues at the elevations we are talking about.

I hate to type this but there is a product on ebay that may help us out. Its a gimmik for 99% of the population but for us it might be the ticket.

Its a high rpm motor hooked to a small fan that is electric (14 VDC). It plumbs into the intake line and pressurizes the intake manifold to about 3 psi. A switch turns it on and off. When off it just has minimal resistance and with my turbo will not be noticed. I am thinking of wasting $50 to see if it will work.


MJPetersen, sorry I could not post photos of turbo earlier but I took a hyd. cylinder off of loader to have a seal kit put in it and was told shaft needed replaced. It will take a week to get new shaft. I cannot open my hood to take photos of turbo until I get the new shaft and seal kit in. IE with loader down hood will not open. I will post photos and more details on turbo once I can open hood. SORRY!

 

[MJPetersen]

Rock there is NO hurry I am just collecting info and am curious. Nothing will happen until winter at the earliest. I have lots to do otherwise before then.

Thanks.
Mike

 

[Mech]

The 1610D did really have low compression, from 300 to 340 psi across the 3 cylinders. The 1610 was supposed to have 23 to 1 compression which at 1000ft equaled 568 to 639 psi. At 8500ft it should have been 431 to 485 psi for a perfect engine. My book saids anything below 400 psi will be hard to start. So you see even a perfect engine is marginal at 8600ft. My 790 only has 18.5 to 1 compression but a different chamber design with top injection. My book says 355 to 440 psi is the specification and doesn't give any altitude correct. I haven't been able to get my dealer to respond to my altitude questions except just to say, "use the cold start aid then, it doesn't hurt anything". I guess it really doesn't hurt anything except these heating coils have, I suspect much shorter life than a diesel engine.