I had a similar problem.

Adjacent to the silver fuel relay should be a black relay. This relay supplies power to the black fuel ECU which, I believe (not 100%) controls the pressure actuator and the part load and full load fuelling. Some of the control also comes from the TPS.

When I had my car set up the relay was not supplying the ecu with power and the fuelling had been pushed up to run the boost but the co at ilde was horrendous which washed the bores.

Once the relay was working the fuelling was set up and is spot on.

What it sounds like is your car is in limp home mode i.e it has basic fuel adjustment proerties to get it home but it cannot adjust for boost.

You may want to check your pressure actuator (located to the back of the metering head. Can be black or grey) is connected. There is a screw inside to up the fuel but I think this is not operating properly.

A quick call to MSD might help you too. They are always good with things like that.