[MA70-3.0GT]

I'd have to disagree with that statement, the kd cable can be to tight & has nothing to do with how hard it slams into gear. All it does is drop back a gear when you "kick down" the throttle and as such needs to be set so it operates at the last bit of pedal travel, or youll be running in 2nd everywhere drinking fuel and killing the motor. To be honest though i think the fault is more likely a sticking valve internally and this usually means a rebuild. You could try adjusting the actual cable/link from the shifter but i'd get a specialist to do that even since doing it wrong can mean the car can slip into gear unexpectedly or even be started in reverse. If the specialist says it is internal you could try changing the fluid before spending out (assuming the level is correct now, make 100% with a hot check first of all before jnything else)