How can i fix my Vauxhall Vectra 1.8?

No power under load indicates a faulty HT system.
I used to work at a Vauxhall dealership and found the plug leads would track through to the head. Pull off the plug connectors and check around the bit which pushes on the spark plug.
If the sparking plugs are in good order and no sign of traking then suspect a dodgy lead (measure resistance - should be 5K to 20 K ohms depending on length) or coil.

His Nibs
March 2009

sounds like you need a new clutch

gary
February 2009