hi people need some help with my golf, its a mk4 TDI 90hp AGR engine, problem is when you put your foot down it will boost up but as u hold your foot down you can hear it dumping boost as if you keep taking your foot of the accelerator when it is actually still planted firmly. you can also feel the car jolt as it dumps again and again, i have replaced the Boost control solenoid located on the bulk head and also the boost pressure sensor (MAP senor) both brand new and still no luck, im now beginning to think its the actuator or turbo but am i right in saying you have to buy a new turbo to get an actuator as its not sold separately.
P.s i forgot to mention had it on the vagcom and it said boost control solenoid valve (one on the bulk head) hence why i replaced that 1st, changed all the vacuums to it as well with brand new ones.
Any suggestions would be much appreciated
Ta james
