had a swatch thru the wiki but can't find an answer,so thought i'd just brazenly ask

1988 caravelle,1.6d,runs fine but absolute murder starting in the morning.
took it to two decent veedub places here and was charged a fair whack with no resolution.
it takes 10-12 turns to get going from a cold start,in all weathers.even if it's left for 30 mins,it's the same.
always eventually starts but blows out a plume of smoke,although it doesn't smoke after this.it's runs great after this,no losses of power or erratic noises or over -revving,nowt,runs excellent (for a 20 yr old van!)
first place i took it to replaced an air intake pipe(?) and banjo washers and charged a rather expensive amount and was told it was working fine-took it home and same problem next morning.not a happy teddy and in dispute with said place.
second place replaced glow plugs,fixed a wire,checked starter and battery and again charged a few bob-told it was fine and took it home-next morning same prob.
apart from the fact that i reckon both places had it warmed up for me coming (it starts no problem when engines warm!) i really can't afford to keep firing it in with no result.
also decent places for fixing type 25's up here are hard to come by.
i also had it checked out by a local auto electrician as one of the places reckoned there was no power going to the plugs but he says there was and my electrics are fine.
i'm 300 odd quid down and it still toils to start and the neighbours are feckin sick of my 6am alarm call!!!
is this a common problem or can anyone offer advice on what the problem is or had similiar probs and found a cure?