1.8 Diesel Escort Van Wont Cold Start

Hi All.

My 2002 (52 plate) Escort Van has become a right pig to start from cold. I have renewed the glow plugs, and have checked the power going to them, so its definately not a "heat" problem, so im guessing (from reading up on the subject on many forum threads) that it is possible that the diesel is going back to the tank? meaning an airleak of some sort?. To try and justified this i took the air intake off one morning and dropped a spoonful of diesel down each pot, put the air intake back on, turned the key, heated the plugs and hey presto it fired straight away, albeit didnt run as it only had the spoonful of diesel to burn, which would strenghten my case that the diesel is running back? Today i have renewed the primer pump on the fuel filter, as i read that these can sometimes leak air, but i still have the problem?......any suggestions? I have also changed the fuel line between the primer pump and the injector pump as both fittings didnt seem that "tight", but that still hasnt cured it. I have noticed that one of the diesel injectors has a leak, could that cause the fuel to creep back??? It seems that i am running out of "cheap" options. The pump timing has been checked, could it be the pump itself? but it does run ok once started, abeit a bit smokey these days (bluey/whitey smoke...related?)

Like i say, i am running out of ideas, would be greatful if anyone could shed some light as to what else i could try. Someone did say there was a "shut off valve" on the pump that sometimes sticks??......couldnt see it (but didnt really know what i was looking for :))

Thanks in advance

Vattie