Poor Starting 2.4 TD

Guys, looking for some advise, now the days are somewhat cooler my landy is stuggling to start,
I have checked and fitted new heater plugs, changed the fuel filter and checked for basic things,
Typically i need to turn the engine over for 30 -40 secoinds before it fires,
Any thoughts on this.

Battery cranking power poss or poor cold start performance

2.4? is it a transit engine?

If not Transit is it a VM??