I have a 1999 2.8 V6 Syncro, it has developed an intermittant fault on the dashboard, when starting the car everything is fine and then the engine seems to misfire very very briefly say about half a second, when that happens the lower panels ( clock and multifunction display) in the clocks go off and they wont come back on until the engine is restarted, i have checked with a VAG diagnostics and its not showing any fault codes, any suggestions on this please.