revs drop when fan kick in

[piotr]

hi .i have got problem with my s2 aby.(my first one )
when cooling fan kick in revs drop very badly or on some ocasion engine just cut out.
i only just got tis car and i know there is a few bits witch need attention.one of them is noisy fuel pump and i just wonder is my rev drop problem link with weak fuel pump???
thank you guys for any advise.

[prj]

Pressurize the intake and check for boost/vaccuum leaks.
Check ISV.

[piotr]

im my workshop we have got smoke machine,is this gonna be good test to do?and please tell me how to pressurise intake?