I`m getting an intermitent problem with the boost.Sometimes i`ll get full boost and the car will pull cleanly right through the rev range and other times it will hold back and judder. I`ve been told it could be an actuator problem, the plugs or coil breaking down, or the boost control valve.Has anyone had a similar type of problem?

 

depends on a few variables ie year/mods

most imho are down to the MAF Sensor. so start there first, or better still do a search for boost problems on this forums

 

Or a sticking waste gate.
One way to tell if your MAF is on it's last legs is when you sit in traffic and the engine is idling eratically. You havn't by chance put a new/replacement air filter on?

 

Havn`t had it long but the car did come with the standard air filter element in the boot so i think it does have an aftermarket filter in.

 

Idle seems ok in traffic. Havn`t had the car long but it did come with the standard air filter element in the boot. I think it is running an aftermarket filter.