Hi mate, there is no fuel mapping on Escort RS turbo's, the pressure is just varied acording to the position of the flap (more air flow sucks the flap down further) in the metering unit and your throttle position.
The fuel pressure will need setting according to your AFR (Air to Fuel ratio) at full load WOT using a wideband lambda.
Unless you have a WBo2 and some Det Cans your better off taking it to your nearest RS experienced tuner, or you risk your engine mate.