[wildturkey]

Vacuum leak?

Get the car to as close as you can to an idle. Then spray a can of general purpose water dispersant spray or carby cleaner around all of you inlet plumbing. One connection at a time. Don't get to heavy handed around the ignition system as you will have a fire on your hands.

You need to check every single point from your air meter to your injectors, including the turbo inlet / outlet, intercooler and inlet manifold gaskets.

The theory is the aerosol spray is a fuel. If you have an vacuume leak and you spray fuel in it, you will momentarily correct the air fuel ratio and the engine will rev up.

It is not easy to glance at all the possible points where it could leak so you need to be systematic and thorough.