Hi. Can anyone help me please? I have an S2 1990 RS Turbo. I am restoring the car and tried to start it up but it won't start up proplery. When I push down on the flap on the metering unit, the car will start and as i rev it I have to manuely push the flap down while using throttle, it rev's then, as soon as i take my hand off the flap, it stops. Any suggestions please? Thanks.