Recieved a Diesel tuning box today for my Audi A3 2.0TDI 140. Followed the instructions on fitment and found the car wouldn't start, it would turn over but not fire. Tried all the connections again, left ignition on for 1 minute and tried again, still not fire. In the end we had to take the kit back off and put the standard plug back on to the engine, it fired up this time but sounds awful. It's juddering badly when revving and pulling away, sounds like a tractor and is gutless...it's vibrating quite a lot too, so much so that I pulled over. I'm now stuck at the start of a 4 day bank holiday weekend. It sounds as if it's misfiring or running on 3 cylinders, or engine timing is totally out?? Engine light is also now on. Any advice on this please?