a recently put engine into subaru and it aint idling correct...when u start it the revs go from bout 1000rpm fluctuating to bout 2000 then when you give it a rev it drops bk down to nothing then stutters and cuts out.Tried few things but running out of ideas, any help would be apreciated cheers

 

what have you try'd????
Think i may have a simular problem........ My rev needle drops when pulling upto light with clutch pressed, drops below 1000 and sometimes stalls.

 

missing vacuum? sensor problem?

 

what sensor? MAF or idle control valve?

 

i had the exact thing! replaced sensors etc,it was a nightmare,the ecu was giving the all clear and it ended up being spark plugs,car has never missed a beat since replacing them,ensure they are gapped correctly before installation!