The first thing to check is the batteries that power your servos. DO NOT use cheap batteries here. Those cheap batteries can cause an accident.
Once you have fresh batteries in there and if your still having a problem, check your wire connections. If that doesnt work it could be the crystal or your reciever.
When you turn on the car does the steering servo and throttle servo twitch into place? Try giving tech support a call, they are nice guys.
