L5740 Cold Start

[Johnbro]

Advancing the injection pump timing reduces the amount of fuel entering the the cylinder and as a result only reducing the diesel exhaust particulates and NOX emmisions. The vibration problem does not go away and is amplified by the slowed crank rotation at idle.

Any inline three cylinder or four cylinder diesel engine that has its fuel pump timing set to ZERO T.D.C. will purr at Low Idle speed even in very low operating temperatures as long as the fuel the proper grade.

We are not living in the Russian federations far east in the Siberian Taiga where they have to drain the radiators and the gear boxes of the vehicles they use to prevent the engine block and differentuals from rupturing from sub zero temperatures.


I would ask your dealer to reset the injection pump timing to Zero T.D.C., as that will solve it for you for the length of time you own the tractor and the indirect injection pump will work very well with less effort.


You spent good money on your tractor and you own it and they are obligated to service it for you; there is no logical reason that it can not be reset to Zero T.D.C. and you will have much less worry and wear on the fuel system.

If the IP timing was retarded, wouldn't there be other problems other than a few seconds of lumpy idle/white smoke at cold start? Things like over heating, excess black smoke, poor fuel economy?

 

[leonz]

Yes but the timing has been advanced on the smaller tractors coming off the assembly floor to reduce the exhaust emmisions and diesel particulates to get under the EPA's current rules and regulations.

The issue is vibration at "Low Idle Speed" and the amount energy created because of the advanced injection pump timing which quite ofte becomes much more pronounced when the engine speed is increased and becomes unbearable.

Its a simple fix after the sale and it can be done quickly to make the problem GO AWAY FOREVER.

 

[Country1]

Yes but the timing has been advanced on the smaller tractors coming off the assembly floor to reduce the exhaust emmisions and diesel particulates to get under the EPA's current rules and regulations.

The issue is vibration at "Low Idle Speed" and the amount energy created because of the advanced injection pump timing which quite ofte becomes much more pronounced when the engine speed is increased and becomes unbearable.

Its a simple fix after the sale and it can be done quickly to make the problem GO AWAY FOREVER.

leonz, do you know if the mid sized direct injected M's (M6040, 7040, 8540 & 9540's) are coming with the pump timing advanced too. Or is the tier 4 emissions being taken care of with the cooled EGR and turbo's only?

Thanks,

Rick

 

[leonz]

Anything above the L series has the
pollution controls in it as far as i know
and the smaller ones have

"the Voodoo adjustments"

as they are strictly sized via the C.C. or Cu In.
displacement per the EPA guide lines which
I added here a few weeks ago.

All they need is a catalytic muffler
"Diesel Exhaust Gas Purifier" and this
business would end and they would
sell more of them and have customers
for life.


The Exhaust Gas Purifiers are easy to add
to any diesel and as long as the motor is
in good condition and the tractor is held
at high R.P.M. while working.

The engines high temperature exhaust gas
emmisions are converted to Carbon Dioxide
and water vapor.

 

[DDT]

I talked with service man to day, He said the tier 1 and 2- 40 series timming specs were 16.5 to 17.5* the teir 3 engines timming specs are 8.5 to 10*. he also told me the tier 3 s had a smaller cam lobe to help emisions.

 

[crazyal]

I don't know about any other GL40 owners but my 4240 is very smooth. From idle all the way up to top RPMs. Sure when it's first started when cold out it's a bit rough and smokes some but so are the other two diesels I own. After a few seconds it clears up and runs fine. I don't think I own an engine that doesn't run a little rough when first started in 0 degree weather.

 

[bitseeker]

I don't know about any other GL40 owners but my 4240 is very smooth. From idle all the way up to top RPMs. Sure when it's first started when cold out it's a bit rough and smokes some but so are the other two diesels I own. After a few seconds it clears up and runs fine. I don't think I own an engine that doesn't run a little rough when first started in 0 degree weather.

I agree. Our GL5240 puts out a little smoke and runs raggedy for a few seconds when first started in cold conditions. It always starts in just a few cranks. It then smooths out and idles like silk. Subsequent starts when warm are smoke and vibration free. Our BX23 acted the same way.

Isn't incomplete combustion (causing the smoke and roughness) normal for diesel combustion because there is no spark, and reliable ignition and complete burn depends on heat and compression which improve when the combustion chambers warm up?

 

[leonz]

Any diesel in good condition no matter the size will have a single puff of black smoke when the combustion cycle starts and then barely any smoke at low idle unless the air filters are plugged.

If you have an extended period of black smoke like the OP and the chugging where you can hear each cylinder complete its combustion cycle with a huge amount of effort and then the following cylinder repeat i would have them examine the timing to be sure its at Zero T.D.C.

If you have ever been next to a railroad locomotive when it is idling its smooth and balanced and you cannot hear each cylinder complete its combution cycle like you would with a diesel with advanced timing.


the above is what you want with your tractor.

 

[bitseeker]

Any diesel in good condition no matter the size will have a single puff of black smoke when the combustion cycle starts and then barely any smoke at low idle unless the air filters are plugged.

If you have an extended period of black smoke like the OP and the chugging where you can hear each cylinder complete its combustion cycle with a huge amount of effort and then the following cylinder repeat i would have them examine the timing to be sure its at Zero T.D.C.

If you have ever been next to a railroad locomotive when it is idling its smooth and balanced and you cannot hear each cylinder complete its combution cycle like you would with a diesel with advanced timing.


the above is what you want with your tractor.

Thanks Leonz,

My tractors have more than a single puff, yet there is no smoke or vibration at low idle after a few seconds.

Above, the specs for a couple of classes of diesel injection timing were quoted:
- Tier 1 & 2- 40 series ... 16.5 to 17.5 BTDC
- Tier 3 ......................... 8.5 to 10.0 BTDC
Are those specs incorrect?
Should all be reset to Zero T.D.C.?

 

[Chilly807]

Interesting thread... I can honestly say I've never , ever, in over 25 years of diesel repair and fuel injection work seen a diesel set at 0 degrees BTDC for start of fuel delivery. Most are between 15 and 35 degrees BTDC depending on the combustion chamber design and compression ratio.

I have attached a picture of the engine label on my 3400, which works perfectly normal in cold weather in my opinion. Notice the injection timing is 17.25 degrees BTDC.


We've recently done some diesel engine testing through work involving attaching a pressure sensor to the fuel injection line and another one attached to the cylinder head to measure the pressure rise in both areas vs. degrees of crank rotation on a running, loaded engine. There is also a sensor in the injector tip to measure when the needle lifts and injection actually begins. With timing set at 32 degrees BTDC, the actual ignition point is approximately 6 to 9 degrees after TDC on the power stroke. Diesels have a phenomonon called ignition lag, measured in degrees of crank rotation from the time fuel is injected into the combustion chamber until it begins to burn. This is a normal facet of diesel operation, and is why fuel must be injected well before TDC.

That's a V16 turbo intercooled engine turning at 1800 rpm and making well in excess of 1000 HP at full power. We had reliability issues that led to a study of what was happening with combustion pressures and fuel timing.

After experimenting with different injection timing, it was discovered that retarding the timing even 5 degrees resulted in excessively high exhaust gas temperatures, poor combustion, and reduced power for an equivalent amount of fuel consumed. Advancing the timing beyond the original design resulted in extremely high cylinder pressures, cracked and broken connecting rods, etc.

That's 5 degrees or less of change, and here we're discussing retarding it over 15 degrees?? Come on people, have some faith in Kubota and the other manufacturers. They DO know what they're doing, it's one of the reasons they're one of the leaders in small diesels worldwide.

Changing timing affects primarily cylinder pressures, but does have a secondary effect on exhaust gas temperature. Changing the amount of fuel delivered affects primarily the exhaust temperature, with a slight change in cylinder pressure. The two variables are quite different and both are independently adjustable on all diesels I'm aware of.

There's a lot more to adjusting fuel timing than most folks realize. You're changing a design parameter that's been carefully set to provide a balance of the best performance and engine life, while still meeting emission standards.

As some have tried to point out, diesels don't work particularly well when they first start in frigid conditions. Cylinder temps barely support combustion, so yes they will run rough and exhibit grey-white smoke until the cylinders warm up. There's normally a puff of heavy black or grey smoke on start-up, then it will reduce to a lesser level and eventually go away entirely as the engine warms up. The governor will keep adding fuel to maintain idle.

Suggesting that the timing should be set to 0 degrees BTDC regardless of what Kubota has designed it to be, makes absolutely no sense to me. I seriously doubt any dealer will warranty an engine that has had that done, I certainly wouldn't.

And that, my friends, is my opinion.

Sean

 

[MyJoBota]

As the original poster I would like to thank all that have shared to this thread. The video has been removed.

 

[Johnbro]

Interesting thread... I can honestly say I've never , ever, in over 25 years of diesel repair and fuel injection work seen a diesel set at 0 degrees BTDC for start of fuel delivery. Most are between 15 and 35 degrees BTDC depending on the combustion chamber design and compression ratio.

I have attached a picture of the engine label on my 3400, which works perfectly normal in cold weather in my opinion. Notice the injection timing is 17.25 degrees BTDC.


We've recently done some diesel engine testing through work involving attaching a pressure sensor to the fuel injection line and another one attached to the cylinder head to measure the pressure rise in both areas vs. degrees of crank rotation on a running, loaded engine. There is also a sensor in the injector tip to measure when the needle lifts and injection actually begins. With timing set at 32 degrees BTDC, the actual ignition point is approximately 6 to 9 degrees after TDC on the power stroke. Diesels have a phenomonon called ignition lag, measured in degrees of crank rotation from the time fuel is injected into the combustion chamber until it begins to burn. This is a normal facet of diesel operation, and is why fuel must be injected well before TDC.

That's a V16 turbo intercooled engine turning at 1800 rpm and making well in excess of 1000 HP at full power. We had reliability issues that led to a study of what was happening with combustion pressures and fuel timing.

After experimenting with different injection timing, it was discovered that retarding the timing even 5 degrees resulted in excessively high exhaust gas temperatures, poor combustion, and reduced power for an equivalent amount of fuel consumed. Advancing the timing beyond the original design resulted in extremely high cylinder pressures, cracked and broken connecting rods, etc.

That's 5 degrees or less of change, and here we're discussing retarding it over 15 degrees?? Come on people, have some faith in Kubota and the other manufacturers. They DO know what they're doing, it's one of the reasons they're one of the leaders in small diesels worldwide.

Changing timing affects primarily cylinder pressures, but does have a secondary effect on exhaust gas temperature. Changing the amount of fuel delivered affects primarily the exhaust temperature, with a slight change in cylinder pressure. The two variables are quite different and both are independently adjustable on all diesels I'm aware of.

There's a lot more to adjusting fuel timing than most folks realize. You're changing a design parameter that's been carefully set to provide a balance of the best performance and engine life, while still meeting emission standards.

As some have tried to point out, diesels don't work particularly well when they first start in frigid conditions. Cylinder temps barely support combustion, so yes they will run rough and exhibit grey-white smoke until the cylinders warm up. There's normally a puff of heavy black or grey smoke on start-up, then it will reduce to a lesser level and eventually go away entirely as the engine warms up. The governor will keep adding fuel to maintain idle.

Suggesting that the timing should be set to 0 degrees BTDC regardless of what Kubota has designed it to be, makes absolutely no sense to me. I seriously doubt any dealer will warranty an engine that has had that done, I certainly wouldn't.

And that, my friends, is my opinion.

Sean

Nice! Thanks for the input and it's good to see some actual data. Very helpful post.

 

[leonz]

Since Kubota in its ultimate wisdom has been advancing the timing to 8 degrees at T.D.C., to reduce the NOX, CO2, and Diesel Exhaust Particulate Concentrations at the exhaust pipe in emmisions tests to comply with the new EPA guidelines for Lawn Mowers With Diesel engines rather than simply leaving them Set and BALANCED as delivered from Kubota-Japan and installing a very small diesel exhaust gas scrubber before the so called muffler what do you suggest the new owners oif S.C.U.T., and C.U.T.S.'s do?, due to the vibration whch can cause potential nerve damage from wood cutters disease because of the massive power delivered and absorbed by the tractors frame and chassis?


You have to understand that the engines are not completely isolated and the throw wieght created by the act of unbalanced loading internal combustion creates huge centrifugal forces where the mass of the tractor is absorbing these forces.

These engines are used in other applications with zero issues OR VIBRATION
so>>>>>>>>>..........................................................:thumbsup:



If you want to really understand vibration you should investigate wood cutters disease.

AND if A "major" Kubota Engine reseller and rebuilder says" THERE SHOULD BE NO VIBRATION at idle; what does that say about what these engines are found to be set at
and when they are reset to zero T.D.C.????????????????

 

[bitseeker]

Since Kubota in its ultimate wisdom has been advancing the timing to 8 degrees at T.D.C., to reduce the NOX, CO2, and Diesel Exhaust Particulate Concentrations at the exhaust pipe in emmisions tests to comply with the new EPA guidelines for Lawn Mowers With Diesel engines rather than simply leaving them Set and BALANCED as delivered from Kubota-Japan and installing a very small diesel exhaust gas scrubber before the so called muffler what do you suggest the new owners oif S.C.U.T., and C.U.T.S.'s do?, due to the vibration whch can cause potential nerve damage from wood cutters disease because of the massive power delivered and absorbed by the tractors frame and chassis?


You have to understand that the engines are not completely isolated and the throw wieght created by the act of unbalanced loading internal combustion creates huge centrifugal forces where the mass of the tractor is absorbing these forces.

These engines are used in other applications with zero issues OR VIBRATION
so>>>>>>>>>..........................................................:thumbsup:



If you want to really understand vibration you should investigate wood cutters disease.

AND if A "major" Kubota Engine reseller and rebuilder says" THERE SHOULD BE NO VIBRATION at idle; what does that say about what these engines are found to be set at
and when they are reset to zero T.D.C.????????????????

So Leonz, you suggest that injection timing at zero T.D.C = zero issues OR VIBRATION?

BTW, Wood-cutter's disease is most commonly attributed to lichen contact sensitivity.

 

[leonz]

Zero issues and zero vibration as it is balanced.

 

[Jerry/MT]

Interesting thread... I can honestly say I've never , ever, in over 25 years of diesel repair and fuel injection work seen a diesel set at 0 degrees BTDC for start of fuel delivery. Most are between 15 and 35 degrees BTDC depending on the combustion chamber design and compression ratio.

I have attached a picture of the engine label on my 3400, which works perfectly normal in cold weather in my opinion. Notice the injection timing is 17.25 degrees BTDC.


We've recently done some diesel engine testing through work involving attaching a pressure sensor to the fuel injection line and another one attached to the cylinder head to measure the pressure rise in both areas vs. degrees of crank rotation on a running, loaded engine. There is also a sensor in the injector tip to measure when the needle lifts and injection actually begins. With timing set at 32 degrees BTDC, the actual ignition point is approximately 6 to 9 degrees after TDC on the power stroke. Diesels have a phenomonon called ignition lag, measured in degrees of crank rotation from the time fuel is injected into the combustion chamber until it begins to burn. This is a normal facet of diesel operation, and is why fuel must be injected well before TDC.

That's a V16 turbo intercooled engine turning at 1800 rpm and making well in excess of 1000 HP at full power. We had reliability issues that led to a study of what was happening with combustion pressures and fuel timing.

After experimenting with different injection timing, it was discovered that retarding the timing even 5 degrees resulted in excessively high exhaust gas temperatures, poor combustion, and reduced power for an equivalent amount of fuel consumed. Advancing the timing beyond the original design resulted in extremely high cylinder pressures, cracked and broken connecting rods, etc.

That's 5 degrees or less of change, and here we're discussing retarding it over 15 degrees?? Come on people, have some faith in Kubota and the other manufacturers. They DO know what they're doing, it's one of the reasons they're one of the leaders in small diesels worldwide.

Changing timing affects primarily cylinder pressures, but does have a secondary effect on exhaust gas temperature. Changing the amount of fuel delivered affects primarily the exhaust temperature, with a slight change in cylinder pressure. The two variables are quite different and both are independently adjustable on all diesels I'm aware of.

There's a lot more to adjusting fuel timing than most folks realize. You're changing a design parameter that's been carefully set to provide a balance of the best performance and engine life, while still meeting emission standards.

As some have tried to point out, diesels don't work particularly well when they first start in frigid conditions. Cylinder temps barely support combustion, so yes they will run rough and exhibit grey-white smoke until the cylinders warm up. There's normally a puff of heavy black or grey smoke on start-up, then it will reduce to a lesser level and eventually go away entirely as the engine warms up. The governor will keep adding fuel to maintain idle.

Suggesting that the timing should be set to 0 degrees BTDC regardless of what Kubota has designed it to be, makes absolutely no sense to me. I seriously doubt any dealer will warranty an engine that has had that done, I certainly wouldn't.

And that, my friends, is my opinion.

Sean

I agree with your well thought out response and conclusions, for whatever that's worth. Retarding the injecton timing by 17.5ï° from the spec is excessive and makes no sense relative to the OP's stated concern. Once you disregard the spec timing, you're on your own regarding engine operation, performance, and engine life. Without the ability to monitor EGT, you can easily damage your engine. I would recommend the OP have his timing checked to make sure is is per spec.

I have NH TD95D with an Iveco Tier II engine. It has a ****** device on pump that's controlled by water temperature. The engine starts with slightly retarded injection timing and then when a certain water temperature is reached (I'm not sure of the exact number but I recall it's like 90-100ï°F) the timing is advanced to the normal advance schedule. It starts an idles well in all temperatures without any roughness except when it first fires in very cold conditions(-10F), just like any otherd diesel I have.

Asking a dealer to change the timing is liable to get a negative response. These engine settings are certified by the EPA( whether we like it or not) and can't legally be altered if they are for emmission controls. Just like our cars. I didn't witness the OP's start up on YouTube. If he has a lot more than the ordinary cold start roughness then maybe he's a got a bad injector or some other mechanical problem. I don't see how retarding the timing will fix it.

As far as the original post, does this machine have a block heater on it? If so, was it used? I have block heaters on( or will have as I haven't installed the NH one yet) and I get "soft" easy starts on my other diesel tractor in the coldest of conditions that we experience in Western Montana (-20F). In really cold conditions use whatever starting aids you have on the tractor to make starting as easy as possible. And get that timing checked.

 

[Chilly807]

Wood cutter's disease, hmm? I'd not heard of it until today, but after doing a bit of research it does seem to be caused by lichen contact. No more cutting wood in me underwear from now on.

A timing check is a good idea, getting a dealer to do it without charging an arm and a leg is going to be the trick.

I had a chuckle when I looked at the engine label on my 3400. Not 17 degrees, not 18 degrees, but 17.25... Not sure how they set for that quarter of a degree, but I'd like to watch the procedure.

Sean

 

[Jerry/MT]

Wood cutter's disease, hmm? I'd not heard of it until today, but after doing a bit of research it does seem to be caused by lichen contact. No more cutting wood in me underwear from now on.

A timing check is a good idea, getting a dealer to do it without charging an arm and a leg is going to be the trick.

I had a chuckle when I looked at the engine label on my 3400. Not 17 degrees, not 18 degrees, but 17.25... Not sure how they set for that quarter of a degree, but I'd like to watch the procedure.

Sean

I have a feeling they set it statically with some sort of special tool. That's how the timing on my TD95D is set. I haven't read the details but there is a special tool involved.

 

[beppington]

I had a chuckle when I looked at the engine label on my 3400. Not 17 degrees, not 18 degrees, but 17.25... Not sure how they set for that quarter of a degree, but I'd like to watch the procedure.

No big deal: Just set it half-way between 17.2 degrees & 17.3 degrees :laughing:

That should be close enough anway :confused2:

 

[leonz]

I only know of wood cutters disease and the nerve damage because of the first diagnosis of Japanese wood cutters who started using motorised chain saws after the second world war which did not have the vibration isolated chainsaw engines which is what I am familiar with and which I am referring to in detail.