You might want to check your main vacuum line
rough idle smell gas
no.fully unajusteble
Either the throtle cable is hanging or the idle control solonoid is not working
A serious vacuum leak could cause that.
Tune up
check your pitman arm and idle arm
The computer does - there is no way to adjust it. If it is improper something is wrong with one of the sensors - that is the most likely problem.
Trouble code P1507 means: Idle air control (IAC) underspeed error
Might this supposed to be IAC (Idle Air Control)??If so, see "Related Questions" below for more
Hey Kulwant==It is probably the idle speed motor not reacting when a load is placed on the engine. Sometimes you can remove them and clean them and they will be ok. GoodlukcJOe
maybe the valve timing is a little bit out
I have a 2000 Windstar and it does this at times but it is normally when I start it and go to quickly not letting it idle down. Also mine has 322,000 with original transmission and motor and it has done it for several years.