Ford Fiesta Forum | Ford kA ForumForum for discussion of the Ford Fiesta. From US to AU discuss this little car and the mods you have done. (Ford Fiesta Forum, Ford kA Forum)
Ford Forums is the premier Ford Forum on the internet. We discuss all Ford models on the forum. Registered Users do not see the above ads. Please Register - It's Free!
Nothing to do with the ignition switch. Look for a vacuum leaks (loose hose in engine bay or failed inlet manifold gasket). You might hear an air sucking noise in the engine bay as well.
Also check the air idle speed control valve is connected and working correctly.