hi my audi s3 in holding back then jerks then clears and drives fine after 3500 rpm. happens when u put ur foot down hard not so much when you build up speed gradually.. but after it clears drives 100% perfect its just when turbo comes in initially. any ideas? nothings come up on the computer. already changed spark plugs, fuel filter, air filter. ive tried disconnecting the maf, no change what so ever. havent changed coil packs yet, could it be the turbo on its way out? any info be much appreciated.