Rickyyyyy

Hi. I have a 98 Seat arosa 1.0, engine code AER. When i turn turn the key it will start, but will not hold iddle. I have to repeat this a couple of times until it starts. After start it holds at about 700 RPMs, wich i think it's a bit low and, besides that it runs great and does not stuter or nothing. It gets worse when its raining or cold. Sometimes i have to open it full throtle and also takes a lot of tries and iven so it will not start sometimes. I have already changed the distributor cap, rotor and coil and cleaned the inside of the distributor. If somebody could help me i would apreciate.