sending of spoofing FM signals to a RC car ?

disturbed:
hmm yea ill look into the servo library :stuck_out_tongue: allthought i am not controlling a servo :S

You're controlling something which is designed to be controlled by the same signal as a servo - from the Arduino's point of view, you are controlling a servo. The usual analogWrite() PWM output does not produce the signal you need for this and would result in exactly the symptoms you're describing; it is no use in this situation - you need to use the Servo library.