The Metro Turbo is fitted with a single 1 3/4" HIF44 SU carburettor. This carb differs from the other SU's fitted to Minis and Metros, because it is a sealed unit. The throttle shaft is sealed as are both the dashpot and float bowl.
This is because the carb is under pressure from the Turbo under boost, so must be sealed to avoid fuel escaping.

Carb connections.
The yellow connection is the pressure sensing pipe, which goes from the plenum to the regulator.
The red connection is the fuel feed from the regulator, & the white connection is the float chamber venting pipe, which should be blocked when the ECU is not used.
For connecting the carb to the fuel pressure regulator click HERE.

For troubleshooting SU carbs click here.