Throttle servo twitches and moves to the fully opened position
 

My throttle servo seems to have began twitching when both electrical components are on. The thing is though it eithe twitches or moves to the fully opened position meaning when I take my finger off the brake it fully accelerates what can the cause be?

The servo control board is likely 'not in the best of health'. Try swapping the steering and throttle channels with the receiver to eliminate the receiver as a cause. If it still does it then it's new servo time I'm afraid.

So swap the throttle and servo lines to see if it still happens. If it does then time to change servo? What's the control board is that the one inside the bottom of the servo?

Yes, and yes.

Swap over the steering and throttle wires on the Rx, see if the throttle servo still has problems - if so, then a new servo is in order. If not, and the steering servo starts acting up instead, then a new Rx.

low and behold you will never guess what happened!!
i took your advice ons witching round the servos and everything you said was right. except one thing.
before i swapped them round i turned the Rx and Tx on and hit the throttle guess what? no twitches i thought hold on its fixed itself?! so then i went gotta be a didgy servo so i swapped them round and everything was fine no problems with steering servo and none with the Rx so i re plugged in original channels and again worked fine.
im thinking some moisture entered the servo and has now dried out as i left it underneath the radiator (the car i mean).
maybe is hould invest in a servo though maybe next time i wont be so lucky