Success at last!! Still a couple of 16016 ???s

[RC-Monster Mike]

I believe it is a voltage cutout you are experiencing. As the batteries run down, there voltage runs down and a hard start(rapid acceleration) will drop the voltage low enough to trigger the controller to cut out. If you put the controller in "race mode" on the low voltage option, it should eliminate this, unless your total voltage drops below 5 volts.