I've got an Escort Gti (1800 Zetec silvertop) which I got off a mate. When I got it, the car idled out of control. I've since changed the Idle Control Valve which seems to have sorted out that problem, only now its got a different issue.
When I first start the car it tends to stall if your not keeping up with the idling, after I drive the car for about 3 mins the car warms up and the issue just seems to dissappear.
Ive been told that the best thing to do is to get the ECU reset on a dianostics machine. Is this right or could there be another issue?

Thanks for looking

Slik