Report "Periotically, only for about 5 minutes after starting my scion xa when the engine is cold, the idle is too low to keep the engine running. The idle is normaly around 1200rpm when starting it cold, but is only about 500rpm at these problem times. Once it has run for about 5 minutes then the rpm goes up to about 1000, then to 700 once it has warmed up completely. Idle control valve? Clean the intake? What? Any ideas?"