tat2cliff

hi people i dont know if anyone can help but here we go anyway, my fiesta rs turbo has developed a running problem which is driving me mad,when i start her and she is on fast idle she runs fine but when she goes on idle she will hunt a little bit, if you touch the throttle it goes however when you drive her she is fine until coming on boost then she holds back a bit like a misfire,if you accelarate really slowly however its not to bad thats if you wanna wait a week to get to 50 mph lol but then why own an rst, i have changed the ht leads, fitted a new cam and followers which were a bit knackered, fitted a new coil pack and map sensor but still have the problem,the car has only done 72,000 miles and runs really sweet apart from this so if anyone has any idears. also there dont seem to be any air leaks althought i have checked i dont know what is the best way to check for air leaks anyway, cheers cliff