2QM15 cold starting.

[newage1461]

When I try to start engine in temps under 60, it cranks & cranks, and smoke comes out the exhaust, but it just doesn't want to start.
I plan on picking up a 12V hair dryer and a hose to blow warm air into the air cleaner intake.
Is the smoke from the exhaust while trying to start normal??

Has anyone resorted to using a hairdryer to assist start engine? When it's a little bit warmeroutside, the engine runs great..

 

[Rob2435]

I always push the throttle on my 3gm a bit forward, giving it more fuel. After cranking a bit more she usually starts, rough at first but starts to run fine after 20 sec or so. I don't have glow plugs...

 

[Ralph Johnstone]

When I try to start engine in temps under 60, it cranks & cranks, and smoke comes out the exhaust, but it just doesn't want to start.

Just for something different, try pre-lubing the engine before starting.

Pull out your stop and crank the engine over for about 10-15 seconds. This will wet your rings. Your engine MAY start a little easier because it can now get the compression it needs.

Also note if the engine (when cold) starts easily again the same day. If it starts easily, it's because the rings are wetted with oil.

 

[Warren Milberg]

In addition to using the hair dryer trick on cold days (and it never fails), what grade of diesel are you using? Most commercial diesel now sold is 40 cetane and I think most Yanmars (at least older ones) call for a 45 cetane rating. I add a cetane booster to my fuel tank and think it helps the engine start faster and reduces smoke (and keeps tigers from attacking the boat....).

 

[Benny17441]

Yanmars do not have glow plugs so the engine is started by compressing the air/fuel mixture to its ignition temperature. Maximum compression is built up by successive engine revolutions but a certain cranking speed is necessary to counteract loss as the engine turns. In older engines the cold thick oil and cold engine parts conspire to cause the engine to turn slower and delay or not attain adequate compression and temperature for ignition. Opening the throttle during start up allows for a larger volume of air/fuel mixture which in turn is easier to compress. Also in well worn engines it may be necessary to give the starter a power boost by combining battery banks. The smoke you see is the unburned air/fuel mixture as it escapes on the exhaust stroke of the cranking engine. As a final note if your exhaust port is below the waterline do not allow the engine to crank excessively as you may draw water into the engine.

 

[Dave602]

In addition to what Ralph posted not only does this wet the rings but warms the cylinders. If you have given it some fuel, turned over for 20 secs or so, let it sit a moment maybe 60 sec or so. The warmed up cylinder will vaporize some of the fuel and she will start up. An old diesel guy showed me that while trying to start up early one year in the cold. Has worked good for me ever since

 

[Bill Roosa]

check to see if you have a heater grid in the air intake. It says "glow plug" on the ignition but it just heats the grid which warms the air (just like a blow dryer) It is a unit between the air cleaner and intake manifold with electrical wires.