I have mentioned this before in another post. When i start my S2 up from cold it fires up ok but then it starts to miss fire when i rev it and then the revs just drop down to 3-400 rpm i have turned up the revs but when the engine is properly warmed up it revs to a 1000 or just a bit over. I have changed my injectors and spark plugs but has made a small difference but its still miss fires when cold. I was thinking if the car was running a bit rich would this cause the problem. How would the car run if it was running lean or rich pls let me know any advice on this would be appreciated

One other thing if you think my car is probaly running a bit rich do you think i should adjust the metering unit slightly by turning the screw anti clockwise to lean it off