[Alan G H]

Does the car start well when hot?
If so, it may be worth checking the valve clearance.
On these older engines the valve clearance reduces, resulting in lower compression when cold.

 

[Alan G H]

What is the problem?

OPEL VECTRA A 1.7TD ISUZU X17DT STARTER PROBLEM???

youtube.com

That doesn't sound as if it is spinning over fast enough.
Could be a lazy starter, faulty battery, bad connections, may even be the alternator not charging enough to keep the battery fully charged.
It sounds as if there is plenty of compression, so the valve clearances are probably not the problem.