'dini turbo hunting and high idle

[rew]

iv sorted out my miss fire on my gordini, it happenend to be a mixture of bad leads and a slipping alternator belt that was really badly worn, but now i have a new problem, the car wants to idle at 3000 revs and then sometimes goes down to 1500 but back up to 3000 as it revs itself, my brother has had had something out of the carb he said it was a screw as it was gunged up, could this be a problem and could carb cleaner do the trick? also the car was hot with the fan keep coming on and off and choke was off. thanks for any info