Yanmar 3GM Cold Start Issue

[Notyetsinking]

On my trip from Baltimore to New London, my Yanmar 3GM30F developed an issue where it would not properly start on its own when cold. It would start a bit then die without help. We were able to get the engine started by giving a bit more throttle at idle through the throttle lever. There is a leak at the fuel injection pump. The engine runs fine once it has warmed up and is able to start on its own if it is not cold. Is the injection pump to blame or is there likely another issue?

[Hesti]

First thing - I would not be too concerned with having to give a bit of throttle. That is pretty normal for a simple diesel at low temperatures.



Second - the engine should have glowplugs which you likely can fire up by turning the key backwards for - some time as the manual will indicate. The use of the glowplugs does help at cold temperatures.


Last - the fuel leak should be repaired. Where fuel comes out, air can get in and that can also cause starting issues.

[Notyetsinking]

Originally Posted by Hesti

First thing - I would not be too concerned with having to give a bit of throttle. That is pretty normal for a simple diesel at low temperatures.



Second - the engine should have glowplugs which you likely can fire up by turning the key backwards for - some time as the manual will indicate. The use of the glowplugs does help at cold temperatures.


Last - the fuel leak should be repaired. Where fuel comes out, air can get in and that can also cause starting issues.

Ok, it is a bit of a hassle giving the engine throttle, I do not have a dedicated throttle level as the gearbox and throttle are connected so I do not know how to do so at the moment without doing it physically from the motor. I do have a warm-up capability and will test this to see if it helps. The fuel leak was just discovered and will be fixed.

[sanibel sailor]

Single lever throttle/shifter will usually have a button to pull out or sometimes pull laterally on the lever itself to disengage the shifter from the throttle. Post a pic of your throttle for starters.

[Notyetsinking]

Originally Posted by sanibel sailor

Single lever throttle/shifter will usually have a button to pull out or sometimes pull laterally on the lever itself to disengage the shifter from the throttle. Post a pic of your throttle for starters.

I am not on the boat at the moment so cannot send a pic of the actual throttle. However, the throttle is some winch handle unit designed to be removed when under sail similar to the Spinlock flush mount throttle control. It may be the spinlock unit, but the labeling has been washed out by the sun.

[Training Wheels]

I can’t imagine starting a 3GM30F without giving it throttle.

[wsmurdoch]

Originally Posted by Hesti

Second - the engine should have glowplugs which you likely can fire up by turning the key backwards for - some time as the manual will indicate. The use of the glowplugs does help at cold temperatures.

I don't think a Yanmar 3GM has glow plugs. I know my 3HM does not.

[smith8273]

following

[Alan Mighty]

Originally Posted by wsmurdoch

I don't think a Yanmar 3GM has glow plugs. I know my 3HM does not; it has pre-combustion chambers.

Affirmative to that. No stock Yanmar 3GMxx has glow plugs.

Advancing the throttle is the accepted and necessary prep for starting, even in tropical temperatures.