My Ford Focus 1.8 Zetec (2002) has lost power and has poor acceleration. Came on suddenly, felt like hitting a pot hole. Engine now starts poorly, have to crank it with foot to floor(almost like it's flooded), but once started idle and reving engine okay. 1st and 2nd gear acceleration okay then feels sluggish, struggles to get upto 60mph. Though acceleration better (but still not right) if revs kept above 3000rpm. No engine fault codes, emmisions test passes. My local garage carried out a 75000mile service thinking that might clear the fault, they've checked compression, cleaned the throttle assembly, and pugged it into their diagnostic machine but no fault codes. Any ideas?