2002 Vauxhall Vectra

Engine Performance problem
2002 Vauxhall Vectra 4 cyl Two Wheel Drive Manual 90000 miles

hi wondering if you can help.I have a vectra, engine management light came on was put on computer sayin misfire on block1. Changed spark plug, was ok for about a week then started playin up again, so then we changed ignition coil pck and new set of spark plugsx4. Wen changed started car and had big ploom of smoke then cleared itself, after a week light has come on again then off then come back on, now cleared codes waitin to see if it comes on again, any advice on what else it could be. Thanks paul
May 5, 2010.

Change plug leads. Check/replace crankshaft position sensor. Could also be a bad injector

Dave H
May 7, 2010.