HELP idle problems NEED HELP!!

[chris61210]

hi my name is chris I currently own a manual 1998 GT and my idle has been acting strange. when i start the car it idles fine, but after driving it for a while when I stop at a light the idle will hover at 1100 for about 4sec then it will drop so low (down to 400 or worse) to the point were it sounds like it stalled out, then pop back up again to about 600 then it stays there. when i am still at the stop light, not moving, I will just touch the gas barely and let off it immediatly and it will go back to about 1500 and stay there for about 5 sec even though my foot is completely off the gas. then it does the same thing, drops down to the point were it sounds like it dies then it goes back up . I recently put a new upper intake plenum, O/R Xpipe, and slp loudmouth exhaust. I dont know if that has anything to do with it. What should I do??

mods-
SLP loudmouth exhaust
BBK 70mm throttle body
BBK Xpipe no cats
BBK cold air intake
trick flow upper intake plenum
ford racing fuel injectors

 

[black_96_GT]

Search forums for IAC problems.

 

[the98stang]

replace the IAC

 

[Stang|ess]

yep, IAC for a million. spray it with carb cleaner, and let it dry.

 

[Mike97gt]

ok enough people said the IAC.. do not whore this thread up with 15 more people telling him to clean the IAC.. any more posts for cleaning the iac will be delete and considered whoring.