The car has been trouble free for about 5 months now (is that a record for a valver!?) but im now having problems with it. When I accelerate as soon as the clutch is released the car jerks violently and then stalls. It doesnt do it all the time and only does it at the point the clutch is released when setting off. It is a bit like being in a car with a learner who lets out the clutch too quick and it jerks and stalls. It doesnt happen at any other point in the rev range only when setting off. Ive replaced the plugs with Super 4s and checked the leads, cleaned the air filter etc but it is still doing it. Any ideas anyone?