now that ive got my clipper on the road ive found a few issues with it that i didnt notice when i test drove it, 1 occasionaly when i turn the engine off the car 'runs on' 10-15 seconds. 2 driving along the car will just cut out with no warning then resolve the problem its self or just die compleatly so in have to pull over but as soon as i stop and turn the key it starts

. it has got an inline filter and that is crystal clear, any suggestions?
thanks
mr mk2