I have had similar problems starting my 147jtd as most of the posters on here. What I've found is that there is a fuel heater on the fuel filter/ water seperator element on the bulkhead. The relay for this is in the fusebox by the battery and if I bridge the terminals it hardly draws any current despite the circuit having a 20 amp fuse?. The heater doesn't appear to be available seperately and the whole housing/assembly costs about £90. So at the moment when its been below zero I put a small fan heater under the bonnet pointing at the filter housing and fuel pipes to the HP pump. When I do this the car starts instantly no matter what the temperature, so I'm thinking maybe there is some water in the filter seperator thats stopping the diesel from flowing properly. I've changed the glow plugs but the old ones worked perfectly at their tips when tested. So I'm going to get a new housing with heater and filter when pennies allow, looking about £120 to diy it.
Be the way, If you are tempted to use easystart don't spray into the intake before it gets to the filter, remove the intake manifold hose and spray in there at the manifold.