Good to know it may not be the capacitor, i was about to unsolder it and try the GTX one .
I just noticed that everytime the esc has those "jolts" things the red led turns on,and we"re talking like 5 jolts a second but happens directly when the car 's on the ground not when i hold it in the air .... damn it...
sounds like your batt can't deliver the power the motor/esc need, or it does have a lipo cutoff...