My car has developed a misfire in vtec all of a sudden and it has me stumped. It revs fine up to 5000rpm and drives fine no sluggishness etc. Once above 5k and into vtec she misfires pretty badly. Ive changed the distributor plugs and leads so far, none of which has cured the problem. I also noticed that the car is idling pretty high even when warmed up.(approx 1100rpm). Im running out of ideas at the minute could it be a partially blocked injector or something else fuel related?? The timing on the engine was also double checked and is spot on. Any ideas people??