I'm pretty new myself but if your throttle needs a nudge to engage you might have to adjust your linkage coming off of your servo. I guess it could be a bad/weak servo as well but for what it's worth that's my opinion. When you have the car off keep the transmitter on and press the throttle a few times. If it still sticks it could just need some adjustment on the linkage or it could be your batteries are low on the car....or a weak servo as well. Hope this helps.