Help!! My Vectra was running fine until Saturday. I parked it up and when I came back 4 hours later it would not start. The engine was turning over and tried to fire up, seemed very lumpy and when I pressed the accelorater it died. This happened 4 times. I left it a minute and tried again, this time it fired up and revved, I was able to drive home no issues, 5 miles. Started fine this morning. Parked at work all day, started car at 5pm and it turned over but would not rev past 1500 rpm while I was sat. I tried restarting 3 times, same. On the 4th turn, I managed to start it and rev it as normal, went to pull away and it just slowed down, would not rev past 1500. Turned it off, restarted it for it to rev and then drive away, got all the way home, 17 miles,plenty of road ends and waiting to pull out with no issues at all. Got home, turned car off, back on and fired and revved ok, felt little bit umpy but not as it was. Any ideas please?