Hello I've got a 1800 75 kombi. Last week she started to backfire and idle shit for about 5 mins then would come good. The periods of the backfiring slowly increased. At the moment we are traveling oz with my partner and 14 month old son Harper and I have found some work in stawell park NSW so it is important that the bus is running. we can't get in to a vw mechanic until next Friday so I am attempting to fix her myself. It is running a crowcam fireball xr700 elec ignition run through a gt40r coil and a ballast resister. Doss anyone have experience with this set up???? What I have checked so far: Fuel flow rate is good Leads are good No vacume leaks I can find Changed out coil Checked connections Had a service on Tuesday but was running fine both when I took it in and when I drove home.the prob was occurring before the service. I would appreciate any help as I can't afford to loose this job over transport.