What could cause the Vauxhall Insignia to have trouble starting?

I have a Vauxhall Insignia and sometimes it has trouble starting. It cranks but won't turn over. What could be causing this issue?

One possible cause could be a faulty starter motor. I would suggest checking the connections to make sure they are secure and looking for any signs of damage. If the starter motor is indeed faulty, it will need to be replaced.

Another potential issue could be a weak battery. I would recommend checking the battery's voltage and if it is low, try charging it or replacing it. It's also a good idea to check the cables and terminals for any corrosion.

It's also possible that the problem could be with the fuel system. I would suggest checking the fuel filter for any clogs and the fuel pump for any issues. If necessary, have a mechanic check the fuel pressure to determine if it's within the correct range.