P38 2.5 DSE cold start problems

I've got a 99 2.5 DSE that had intermittent overheating problems that cured themselves before I got around to investigating. Eventually the viscous fan seized causing a massive temp rise and a split rad. I had the rad and fan replaced but ever since the beast struggles to start when cold. I sometimes have to crank it over for up to 15 seconds before it fires up.
I was advised that the glow plugs may have been damaged so I renewed these with no improvement.
When warmed up it starts up, first turn of the key, no prob's, but with winter approaching I am a bit worried about the cold starting.
I have ordered some silicone tubing to renew the injector leak-off pipes, but not arrived yet.

Would really appreciate some advise and ideas.

Many thanks.

Advice and ideas........................................Well, this is the introduce thread, so what about saying "Hello", and asking your questions on the appropriate thread???

Hello.