Sounds like the same problem i have, mine doesnt worry me as it sits in the driveway due to use of a work car. I really should sort it, and have had a look into it before with @Subirex Automotive and the few things he said it could be without having the car for too long could be, Neutral position sensor, timing, coil pack, afm, spark plug gap. @axle117 if possible would like to try those leads and coil pack.