Lumpy Starting

[jofestus]

Hi Everybody,

I have recently purchased a P reg'd Previa and it appears to have developed a problem upon first starting. It seems to have an erratic idle which goes up then down and the car struggles to accelerate. When you change gear there is aloud clunk which I assume is due to the idle speed going up and when you pull away it jerks forwards,(again i assume due to idle) I have tried running injection cleaning treatment in the hope it was a dirty injector or such like, but there seems to be no difference.could it be a problem with the air flow sensor on the air cleaner, or maybe the O2 sensor on the exhaust as it sounds like it might have a slight exhaust blow?

Any help or suggestions would be welcomed, thanks in advance,Joe