Rav,
As Trikey says check for power to the pump first, before dipping your hand in pocket.
Read this thread in depth, the thread has a number of photos showing the pump assembly in bits and the pattern pump. This thread included a couple of turbo models and your car that I experimented with in 2018 in my quest to get rid of the occasional stutter at full pelt on a heavy load that turbo models seem to suffer from. There is an alternative pump available without buying the complete assembly. You will see the issues I had with it. In fact I think I still have the pattern pump which I never used in the end if only I can find it?
https://www.the75andztclub.co.uk/for...1&postcount=35
https://www.the75andztclub.co.uk/for...0&postcount=34