I have a ford focus 1.6 '99 ,72k miles up,that when stationary at traffic lights idles very erractically and sometimes the engine cuts out. check battery 12.48v ,alternator on bat reads 14.89v.The engine doesn't sound as if it is misfiring,
Any suggestions, could coil pack be on the way out?. Would a leak in the air intake hose give this system or dirty MAF ?
Its probably the idle speed control valve. Its on the top of the inlet manifold. Its a cylindrical shape with wires connected to it. Get contact cleaner and spray it up.