I do the same as Koos. Just make sure to immediately reduce the RPM once the engine starts until it warms up a little.
Unlike a carburetor with an acceleration pump, there is no extra squirt of fuel that goes into the combustion chamber on the mechanically injected engines. Opening the throttle really provides a richer mixture until the engine starts (more fuel, same volume of air). The 2GM doesn't have glow plugs to preheat the cylinder. I've seen some Universal diesels that absolutely refuse to start below 50 degrees unless the glow plugs have been run for 30 seconds. At least we can start the 2GM without glow plugs.