UK Car Repair: zafira problem, vauxhall vectra, crank sensor

Question
HI JOHN
I DRIVE AN OPEL ZAFIRA 1.8 16V ON A V PLATE IT HAS ONLY DONE 56K, THE ENGINE CODE IS X18XE1 AND IT IS SERVICED REGULARLY. LATELY IT HAS DEVELOPED A PROBLEM, IF THE REVES DROP DOWN TO LOW IE BETWEEN 1OOO TO 2000 RPM THEN U TRY TO PULL OFF IN THAT GEAR THE CAR STARTS TO JUDDER, U THEN HAVE TO EITHER CHANGE GEAR OR DIP THE CLUTCH AND REV IT A LITTLE THEN ITS FINE AGAIN. AND SOMETIMES WHEN I ACCELERATE HARD THE CAR STARTS TO JUDDER AGAIN SO I HAVE TO EASE OFF AND TRY AGAIN. IVE CLEANED ALL THE PIPES OUT AND THROTTLE HOUES OUT AND HAD A NEW AIR IDLE VALVE FITTED.  ANY ADVICE WOULD BE APPRECIATED
THANKS AGAIN  SCOTT

Answer
Sounds like an EGR problem and or an ignition misfire due to a dying coil or a bad crank sensor. Take it in and have them run a diagnostic scan to see if it is registering a misfire on any of the cylinders and if so if it corresponds with an odd sensor reading. I would lean more towards the EGR than the ignition due to the same problem cropping up in Vauxhall Vectra and other GM products.

Regards,

John