I have a mk4 fiesta fitted with a 1600 zetec se from a zetecS. When i start it the revs rise sharply to 2500 then fall to 1100 (idle too high?). Also between gearchanges the revs are too slow to drop meaning i dont get the full effect of engine braking and jerky gearchanges. The revs also rise to 2000 when i slow up to a stop - very annoying. Any suggestions would be welcome.