Interesting one this and hopefully find an interesting answer. Doesn't start sometimes, other times it starts ok and then performs its function. Maybe the RAC approved garage found an answer but it wasn't the actual EGR valve, does this EGR have wires to it and electronics. Is this a wiring fault problem. Doesn't sound like Fuel related as of air in fuel but maybe has more than one fault. Was thinking of a sensor fault where crank sensor would shut engine down and not leave fault code but it runs ok at times for many miles. Then there's the Boost/temp sensor, shut down yes, leave code, well sometimes. If it goes into limp mode on booting it code P0235 or likes is left. But noticed on mine when boost sensor totally lost it and shut down happened there was no code, as like crank sensor. But that EGR system needs checked and wiring verified.
