Interesting results from a cold-start experiment

[Clark]

I had read on here a report from someone that had been taught by a marine diesel training instructor to do this before a cold/long term disuse start:
Close raw water intake and fuel; crank for 10 sec, rest for 5 sec, crank for 10 sec, rest for 5 sec. open valve and fuel stop then crank engine. The purpose was primarily to push any water in the system out before trying to start to avoid a water lock (pre-oiling the system doesn't hurt either).
At any rate, I tried the procedure this past weekend (temps in the low 40's w/ previous night at ~ 30) and while I was doing my prelim. cranking, a white smoke came out from the exhaust. Obviously not steam (?); the small cloud did not dissipate quickly - so I surmised unburned fuel - but the fuel stop was closed!

BTW, it is a 2GM20F lightly used for 12 years - and it did not start after 2-3 attempts so I just buttoned everything back up.

Any ideas as to smoke/vapor source? Is it possible I did not have the fuel stop fully engaged? Was it still too cold to start w/o doing the hair dryer trick?

 

[Jalepeno]

Just started up my trusty old and reliable YSM12 yesterday to warm here up. Outside temperature was about -1C (that is about 30F for those that are metrically challenged) and I hadn't run her since the end of October. Checked the oil, turned the oil filter wiper a couple of revolutions (only YS*8/12 owners will know that one), opened the cooling water valve, tuned on the battery and key switches, set the regulator to about the 1/2 position and pushed the starter button. She started in about three revolutions. The YSM12 is a simple single horizontal cylinder diesel without glow plugs or preheat. She always starts first time every time. Never had to use WD40, hair drier, etc. I always thought all diesels are supposed to start like that.

 

[Clark]

Just started up my trusty old and reliable YSM12 yesterday to warm here up. . . . . I always thought all diesels are supposed to start like that.

I did too. That is why I'm concerned. Many people have reported slow starting in cold weather for small diesels but What I've seen worries me.

 

[Scott]

I too have a 2GM20F. I don't recall any starting procedure like that in the diesel course I took when I bought the boat. In 20 years and with proper maintenance, starting has never been a problem in any weather. Occassionly in colder weather, it took 2 or 3 cranks, otherwise usually 1 turn and it fires up. Try not doing what you did and see what happens.

 

[seadaddler]

Mixing Elbo

When was the last time you checked or cleaned the mixing elbo.
I found that a partially clogged mixing elbo will result in hard starting in cold weather.
Nick

 

[Clark]

I have not done anything to the elbow. We've had the boat 3 years and I doubt the engine had over 50 hrs on it when we bought it. I'm sure the original owner didn't treat the engine properly as his slip was about 50 yards from open sailing. I do have some weeping fuel fittings that I'll address over the winter but I was surprised that I was getting 'smoke" from just turning the engine over with the water and fuel shut off.

 

[Don12364]

What they omitted to mention was to operate the decompressors whilst running the starter. With nice fully charged batteries you can overheat and burn out a starter on full load after just a few 10 second runs. The manufacturers are silent on this issue but consider putting 1.5KW into such a small motor and how does the heat dissipate?
Running the starter with the decompressors open considerably reduces the loads on both battery and starter.
Even then I feel it would need 5 minutes to cool before trying to start the engine.

 

[Steve Dion]

Clark:

I "thought" the procedure for cold starting was about 2/3-3/4 throttle and hit the key. If the engine does not start in 10-20 sec. then you should close the raw water intake (if it is not already closed) to prevent flooding the cylinders.

The throttle advance procedure is to advance the engine timing (I could be all wet here, but that is what I remember).

 

[Dan Hill]

The white smoke is atomized fuel and air. This is what ignites inside a diesel combustion chamber if all conditions are right. What you lacked was heat. The procedure you described, crank, wait, crank, wait, is done to help generate heat and to help it soak into the head and block. This same procedure is recommended in all diesels, land or sea, and especially on older harder starting designs. Newer diesels use such fine fuel injection orifices under very high pressure that the fuel comes out looking like smoke, which com-busts easier. Any diesel mechanic will tell you that where there's smoke there's fire soon. If you have smoke it's close to firing.

 

[sailaway78]

Small diesels

Small diesels, especially those without glow plugs, are often harder to start when it gets colder. I have found on the two I have experience with, that they start much easier at a particular throttle setting. Previous boat, with a 2qm Yanmar, wanted full throttle for cold weather starts. Current 3GM wants about 1/4 throttle. Experiment around a little bit, and find your engines sweet spot, but do not expect a small diesel, without glow plug, to fire off with only one or two revolutions.

 

[TFrere]

Re: Small diesels

Has anyone ever tried to install glow plugs on your engine? It seems as though a small drilled and tapped hole through the head on each cylinder with some wiring for the glow plugs wouldn't be too tough a job. I have a 3QM30 on my Morgan 382 and have fits trying to start it in cold weather. My last boat had a 2GM20F and was tough to start in the cold too.

 

[Dan Hill]

Intake Heater

Has anyone ever tried to install glow plugs on your engine? It seems as though a small drilled and tapped hole through the head on each cylinder with some wiring for the glow plugs wouldn't be too tough a job. I have a 3QM30 on my Morgan 382 and have fits trying to start it in cold weather. My last boat had a 2GM20F and was tough to start in the cold too.

Many smaller diesels utilize intake air heaters instead of glow plugs. I think this would be an easier retro fit. The hair drier trick performs the same function.

 

[Bud22569]

I use the hair dryer trick on cold mornings (less than ~45 F)when I am in a slip. I found myself anchored out one cold morning with no power for the hair dryer. My engine is a raw water cooled YSM12. I drained the water jacket of the block and then filled it through the anoide hole with warm water from the tea pot. I gave it a few minutes for the warm water to heat the engine and it then fired right up.

I wish Yanmar would have put glow plugs in all of their engines. The Yanmar diesel in my John Deere tractor has glow plugs and will start immediately even with the ambient temperature well below freezing.

Compression should not be the problem with my cold weather starts. My engine has less than 50 hours on a rebuild with a new head, pistion, rings, cylinder liner, injector, and many other parts. I have checked all of the other items that the diesel gurus say would cause hard starting. I am changing the injector pump over the winter to see if this may help with the cold weather starts.

I believe the Cummins diesel engines in Dodge pickup trucks do not have glow plugs. I think they have a heating grid in the air intake as described by WrenchBender. I think the heating grid is probably the easiest modification to help with cold weather starting problems when all other potential problems have been addressed. Perhaps a good quality DC powered blow dryer instead of the tea pot starting system.

 

[Bill Roosa]

Well I thought you

held the decompression lever open, some one cranked the engine and when it got to max cranking speed (2-3 sec) you let go of the decompression lever.
This has worked for me both times I have had to try it.

 

[ScottyIrwin]

I have a 4JHE yanmar and it starts in the cold after 2 revs everytime with no glowplugs. Its something to do with the injection method.

 

[larryw]

Your biggest problem, and the easiest to solve, is non-use. You're not doing the engine any favors by not using it or babying it. Run it hard under load for ten minutes every time you go out is the best thing for it.

 

[RTB]

held the decompression lever open, some one cranked the engine and when it got to max cranking speed (2-3 sec) you let go of the decompression lever.
This has worked for me both times I have had to try it.

Bill, what throttle setting do you use? I'm have the same issues as above on my 3GMD.

Also, do you direct the heat from a hair dryer at the injectors, or air filter?

 

[druid]

I agree that all that cranking (with compression ON) is designed to heat up the cylinders. I agree that Yanmar REALLY should put glow-plugs in their engines - the Universal was SO much easier to start! And you shut off the water so you don't fill the waterlock muffler and backfeed into the exhaust. I guess you shut off the fuel so it doesn't try to start.

...And I think that's where your problem is. All that cranking with the fuel shut off probably created a little air-gap somewhere in the HP system, and the 2GM20 is famous for being impossible to start with ANY air in the system. If I'm right, you'll need to do a FULL bleeding procedure.

I used to crank mine over for 5-10 sec on idle, thinking that would warm up the cyls, but I found it actually started faster if I just gave 'er full throttle. After about a month sitting ("ambient" air from -4 to +8 deg C, probably +3 to +6 on the water), she fired after maybe 5 sec at full throttle.

druid

 

[Jalepeno]

I agree with "druid".
As per my earlier post, my YSM12 starts within the first couple of revolutions in all of our local temperatures from -4C to +28C. Just giver her between half and full throttle durring starting. The decompression lever is usfull to get up to speed if your batteries are low.

 

[Bud22569]

Bill, what throttle setting do you use? I'm have the same issues as above on my 3GMD.

Also, do you direct the heat from a hair dryer at the injectors, or air filter?

I blow the hot air from the blow dryer into the engine air intake. It makes a big difference for a diesel that has trouble starting in cold weather.