I hope someone can help me with this...

Vehicle is Ford Courier Diesel with Enduro 1.8 engine. V reg 85k and no real problems before this;

I cannot get more tha 50 mph in 5th as it judders and splutters just like fuel starvation or a blockage. After it has done 10-15 miles the problem gets worse. Up until then I can get 55 but when it warms up the top speed drops to 40 - 45 with less in other ears. Revving in neutral is also impossible past a certain amount before it splutters and holds back. When you go uphill and start to change down the speed drops and drops until you are doing 10mph in 2nd. If you then knock it into neutral, it stalls and you can't restart it for a minute or two. When you do it behaves for a mile before the cycle restarts...so what to do? What should I check and in what order? I figure that changing the fuel filter would be a good place to start, plus I have a spare set of (nearly) new injectors.

I guess I am hoing that someone who visits here has come across this type of problem before.

Thanks as always,

Axxe