My personal belief is that the pump timing isn't going to affect the cold start in a significant way. If it's two or three or four degrees late, it's really not the issue. The timing affects fuel economy more than any other parameter.

Whether you start in one second or 15 seconds is heavily dependent on the air temperature in the cylinders. To get the maximum air temperature, you need very good compression, perfect valve seats, and a very good battery with a decent starter. The engine must turn over quickly when cold. If the compression is good, it starts immediately.

Naturally, I'm assuming the glow plugs are functioning properly.

Pete Burton once started the 617 with the IP timing out by 180 degrees. Engine didn't have a problem starting.........just wouldn't produce any power and put out massive quantities of smoke. If you're out anthing less than 5 degrees, don't bother with it.