The only thing that would put your revs up is

1. iscv (as stated above)
2.sticky throttle boddie (doubt it but might be worth checking)
3.faulty tps


let the car dry out you might just have water in some where spray all your electric connectors with wd40 or sparky cleaner (ask a sparky where to get it) is your car dragging in to much air on the inlet side?have you checked? that could also put the revs up aswell