My 1.6 16V Vectra LS P reg has the following intermittently problems.
During the winter months, on cold damp days, after being left standing for a long period of time, the engine starts without a problem. After driving for a short distance, usually when I reach a slight incline the car looses power and if I stop accelerating the engine cuts out. It is difficult to restart, but once started there is no further problems.
During the summer months the symptoms change: The engine is some times difficult to restart from hot. The engine seems to be more responsive when the fuel tank is completely full. When it drops below ¾ the engine judders and lacks power. Two different garages tell me there are no problems detected by their computers.
I'm not sure if the symptoms are caused by more than one problem. Please if anyone has any suggestions please help.