diesel start in cold with no fuel

[cal40john]

Someone told me that in cold weather if you pull out your fuel shutoff and crank the engine a little first, it makes it easier to start. I believe he said you're heating the engine due to the compressions. The fuel injected carries away some of the heat, so no fuel lets engine heat up better.

Doesn't sound like it would make a significant difference. Anyone hear about this or thinks it works?

[ozskipper]

I havent heard of it. Not to say it doesnt work. But the cylinders are compressing and somewhat heating during the normal start process anyway.

[gjordan]

It would take a while to heat things up, and you would probably fill the exhaust with water in that time. A few revolutions to get oil pressure up is not a bad idea, but lengthy turning could defeat your purpose, or damage the engine. Just my opinion. ____Grant.

[markpierce]

I want/expect my JD4045 to start within one second. See no benefit but only risk of turning the engine over "dry."

[cal40john]

Originally Posted by markpierce

I want/expect my JD4045 to start within one second. See no benefit but only risk of turning the engine over "dry."

Well that's nice for you. I have no intention of swapping out my motor. My Yanmar has no glow plugs and when the weather is near freezing it has to crank awhile before it starts. Other posts suggest that this is normal for this engine. It has always started (except when there is air in the fuel lines, but that is a different problem), but someone suggested to me that this procedure would reduce cranking time.

[Dsanduril]

This is standard operating procedure (almost) on Volvo's, it's even in the manual. However, you pull out the stop lever and then push it back in before cranking, so you're not cranking without fuel.



Showing my mechanical ignorance, I know this sets something mechanical in the fuel delivery system, but not sure what or how it works. Don't know if the same is true of Yannie's. Maybe your advisor is used to Volvo's?

Edit - Ask the internet and though shalt receive. "cold start device was non-functional. It is designed to advance the injection pump timing for cold starts". That's for Volvo's cold start device using a Bosch injection pump. No idea if Yanmar uses something similar.

[gjordan]

For over a third of a century, Caterpillar diesels were started by a small gas engine, geared to the diesel. Start the pony motor(starting motor) and engage the big engine with the gear and clutch that joins them. Compression release open, and turn the big engine for anywhere from a few minutes to 20 minutes , depending on ambient temp, with the fuel in shut off position. Compression is closed (on) after a few minutes, and the engine heats up enough to start when the fuel lever is advanced. I dont believe it has ever hurt a Cat diesel to be turned with no fuel, and I dont believe it will hurt a marine engine. Again, the danger in a marine engine is water building up in the exhaust which can make starting harder, or can do major damage. A couple of revolutions to get oil pressure up is not a bad idea, but long time turning is a problem. Just my 2 cents worth. _____Grant.

[OnTour]

My 3gm30 has no glow plugs either....the manual says to set the throttle at full position for a cold start.

[markpierce]

Originally Posted by cal40john

Well that's nice for you. ...

Was responding to gjordan's post (immediately before mine), not yours.

[a64pilot]

Why not use a little ether? I've started cold Diesels with a little gasoline on a rag and held the rag over the intake. I do not suggest this unless in dire straits on a boat, but it will work.
In theory the OP is right, the unburned fuel will absorb a little heat, but as they suggest, it's not enough to matter.
Best way I have found to use ether is spray a little into the intake when the engine is turning over, many people spray it into the intake prior to spinning the engine successfully just by doing it with the engine turning is a little more conservative. If your on shore power electric pre-heat is very helpful, sometimes all that is needed is to hang a 100W light bulb near the engine overnight before starting

[evm1024]

IN very cold weather I've started a Yanmar 3HMF while at the dock by pointing the hot air from a hair dryer at the air input. Having preheated air made it start much quicker.

[gjordan]

My Perkins 4-236 has a threaded boss on the intake manifold for a preheater. It is not installed on my engine, but in very cold climates it would be a great help. I think my previous 4-154 also had the place on the manifold for the preheater/airheater. It is much simpler than glow plugs. I wonder if any small diesels have a spot like that on the intake manifold? I agree with previous posters, that with an engine in good condition, and not in very cold climates, that normal starting procedures should work. Just another thought. _____Grant.