yanmar cold start device

[bud4410]

has anyone had any experience with the "cold start device" on your yanmar diesel malfunctioning? on my 3520 it works perfectly i.e. when outside temperature gets around freezing it changes timing on a cold start which results in lots of exhaust smoke and running rich for about a minute or two. however on my 997 lately with the temperature at 50-60 degrees it is doing the same thing when there is no need to assist the engine in starting. probably no harm done but is sure smoking up my garage. anyone have this same problem? let me know your experience. thanks.....................bud

 

[beenthere]

Not exactly sure what you mean by "cold start device" when you say it changes timing on a cold start. It is up to the operator to determine how long the heater stays on. I find when I don't leave it on long enough, I get smoke.

The manual says this:

9. For cold weather starting, use the intake air heater system. Activate the intake air heater system by pushing in the ignition key switch with the key, and holding it there for the required time:

• 10 - 15 seconds for temperatures as low as -18?C (0?F).

• 15 - 30 seconds for temperatures below -18?C (0?F).

 

[greg_g]

The pre-heat system on the 3520 consists of 3 glow plugs. No timer. Matter of fact, no computer assist at all. The length of the "glow" is strictly determined by how long you keep the keyswitch pushed in. Check your manual for specifics, but the general rule is "the colder it gets, the longer you glow". That said, the engine is also direct injection. Granted it never even got into single digits here this winter. But even in the teens, my 3720 started just fine without using the glow plugs

No smoke either, so I suspect you may have at least one bad glow plug. One or two are heating enough to promote compression ignition in the respective cylinders. But a dead glow plug will leave a cold cylinder. Fuel may not initially explode, and come out the exhaust in the form of white smoke. After the piston pumps up and down a few times, the cylinder gets hot enough to support combustion, the fuel explodes, the white smoke turns to grey and eventually disappears.

All I know about the engine in the 997 is that it's also direct injection, but has an intake heater (as opposed to glow plugs). My old YM240 had an intake heater as well. Unlike glow plugs - which only need electricity - the intake heater needs both electricity and fuel. Yours may not be getting one or the other.

//greg//

 

[bud4410]

hi beenthere, thanks for getting back to me. i'm not talking about the intake air heater but what i understand is a epa mandated device which the mfg has to put on all diesel engines. look at your water pump and you will see two flexibe water lines that go to the injection pump. there is some kind of "thermo sensor" in the injecton pump at that point which advances the timing when outside temperature is around freezing till some heated water reaches it very shortly after the engine starts (one to two minutes)and every thing returns to normal and the engine runs smoothly. i found this info by google "yanmar service manual fuel injection equiptment model ypd-mpl/ypd-mp4 series" pages 20-21. i think these devices are on the most recent engines. my 3520 tractor is a 10 and the 997 ztrac is an 11. this is also mentioned in the tm2138 3000 twenty series tech manual on page 37. "on the TNV engines there are small coolant lines between the water pump and the cold start advance unit on the fuel injection pump." sorry to ramble. hope this explains it. thanks for your time...........bud

 

[beenthere]

That helps some. Don't have that problem. Might need to see your Deere dealer and see if they have a bulletin out on a fix, or some recommendation.
I was thinking the intake air heater. I don't see the parts you mention in the jdparts for the 3520. Do you?

The smoke would be annoying.
Maybe it is a deviant plan by EPA to get us to stop buying Deere's as they smoke a lot? Seems they would be against smoke, as they are against everything else.

The manual says, regards smoke.

Engine Emits White Smoke

Improper type of fuel.

Low engine temperature.

Defective thermostat. See your John Deere Dealer.

Faulty cold advance device.

 

[greg_g]

I think there's still some confusion over your issue. Please clarify if this "smoke" problem is with the tractor or with the mower. If it's with the 997, you might get more mower-related responses at the John Deere Lawn & Garden section of this website.

//greg//

 

[bud4410]

hi greg, the problem which is intermittent is with the 997 ztr. have never had the problem with the 3520. since same type of yanmar with the same components on both i felt i would get better exposure on this site cause there a lot more tractors with this setup than mowers. thanks for your interest....bud

 

[greg_g]

hi greg, the problem which is intermittent is with the 997 ztr. have never had the problem with the 3520. since same type of yanmar with the same components on both i felt i would get better exposure on this site cause there a lot more tractors with this setup than mowers. thanks for your interest....bud

Not the same engine though, which may have you comparing apples with oranges. So for the moment, I'd recommend taking the 3520 completely out of the equation. Concentrate on what technical data you can come up with for the smaller engine in the mower.

Most of us won't have access to the references you introduced in the opening post. If we're to consider them in reference to your issue, copies and/or cut&paste segments would assist greatly.

//greg//