hi i put erst s2 mfi engine into a mk5 escort it ran fine with the external fuel pump of the rs turbo but now i have put a uprated cosworth intank fuel pump on and its doing 15mpg it was doing double this previous to fitting new pump how can i solve this problem and why is it happening is it the higher pressure of the new pump and will a rolling road set up fix my problem my car is booked in for tuesday so i could do with nowing before then please cheers tim