sort out your throttle linkage. if you take of the air filter without the engine running, turn on the electronics. full throttle then brake see how far the throttle closes. i used to have the same problem, what u might find is when you apply the brake the throttle closes a little more than when its idling even if it closes by about 1mm its still alot, trust me. correct throttle linkage is the key to performance. you'll know when you get it right but some cars take longer thatn others. experiment. hope i've been some help