1.0 3 cylinder misfire

[soakes94]

I've just bought a 12 year old (X Reg) corsa, 1.0 litre 3 cylinder and it seems to be low on power, 50mph is its top speed, 60mph if I'm going downhill. It also seems to misfiring when I accelerate hard or if I'm putting alot of strain on the engine, like going up a hill. I had a mate whos a mechaninc look over it but he says he cant see anything obvious. Anyone got any ideas? Im getting the car back tonight of my mate. Ive got a basic understanding of cars, I was thinking maybe spark plugs, bad sensor? Any other ideas? And does anyone know if I can do a paper clip test on this? Since that might save me alot of time and money.

Cheers
Steve

[miles123]

Could be your mass air flow meter, try unplug the sensor for this and then see what it drives like

[soakes94]

Had a mate have a look at it he said that:
1. checked fuel pressure 3 bar spot on
2. checked lamda sensor showing constant 1volt at idle
3. Spark plugs are white running lean
4. Removed lamda sensor at drove no difference not a blocked cat
5. Disconnected air mass meter and drove no difference
6. Disconnected coolant temp sensor and drove no difference

Took it to a garage and they changed a sensor, cant remember which one and the EML has gone out and its topped speed has changed from 45mph to about 60/65mph. It is still missing a little though, getting the filters changed on Saturday so hopefully that will stop it missing completely.