Will not idle 2003 ford focus

Idles rough start, after warm up, driving short distant, shut off engine, several stop , starts, then will not idle. automatic , 120,000 miles
Please help.

The problem might be caused from a dirty/defective Idle Air Control valve. The next time the engine won’t idle, slightly step on the accelerator. If doing this allows the engine to idle then the problem is most likely with the IAC valve.

The IAC valve is mounted on the throttle body. You can try removing the valve and cleaning it along with the idle air bleed port on the throttle body with throttle body cleaner to see if that fixes the problem. If not, then the IAC valve my require replacing.

Tester