In other words it's getting lazy!

It plays up when the car hasn't been used for a while, it will read low or not come up off of idle when being driven, after 20mins or so it normaly comes back to life. But today it's not playing ball, now it goes up to 4000 but won't go beyond it, any reason why this might be or is it just a case of getting a new speedo unit?

Oh and i'm away for a few days working so if i get some replys and don't give any feed back it's coz i'm not here

Cheers guys.

Bad ground connection.

Ok mate, thanks for that, i'll check it out later today