your have to get ys finger up the back of the pedal and push the arm up and get the quadrant round and them let the rachet arm down again, push on the cluch a couple of times, slow and easy, dont boot it to the floor, and let it set it self, if the rachet it self has worn teeth it will slip back round and make no diffance.

im not saying this will sort the problem but it has for me before in the past on one of my first fiestas as well as a couple of mates fiestas, other times ive had to replace it, its worth a shot at least