erratic idling

[xtreme42]

I have a 2000 mustang GT 4.6l sohc. Initial problem was the car would start then immediately die. Now starts fine but slight rough idle. Now with A/C on then put into gear, will idle from 400 rpm to 1200 rpm and eventually die. If put into gear then turn the A/C on, no erratic idle and will run but still slight rough idling. Any thoughts?

 

[GDawg]

Check for vacuum leaks first. When was the last time the fuel filter was replaced? When was the last time you cleaned your injectors?

Start with that. You could also have a bad or dirty IAC. Or bad fuel pressure regulator.

 

[Morgstang]

mine did the same thing and it was the IAC..