lrp tc spec problem!!

[trf415]

i fitted the esc on christmas day and it worked fine
but when i came to turn it on the next day there was no throttle.
the steering servo worked perfectly fine
i am running a ko propo esprit 2 and since buying it i have reset it
i have changed the sensor wire and nothing happened
if i spin the wheels whilst moving the throttle forward it works fine but when the wheels stop turning you have to restart the process of turning the wheels.

thanks in advance!