I had this problem when I had my SVT. I eliminated the problem by liberally spraying the linckage at the throttle body with carb cleaner, exercising the accelerator pedal full travel several times(witht the engine off) followed by forced air drying with compressed air regulated to 20psi, followed by a spray until it drips with LPS1 (a PTFE lubricant) don't use a oil based lubricant becasue it will attract dust and dirt.
