[northernblue]

Update , fitted a different vacuum pump ,still no luck.

If i pull off the vacuum pipe (the one that goes to boost solenoid),then pump the brake pedal the popping goes away,until i stop pumping.

If i pull off the brake booster pipe the popping also stops until i cover it or put the pipe back on.

I don't have full turbo at motorway speeds but the car pulls way better than in 2nd or third.

Any ideas ?

Cheers