weird idle in park

akaslick15 · Feb 25, 2012

so its a 94 mustang gt auto so i just recently just got this problem so i went inside the gas station and as i hear my car i had thought sombody was revving it lol sounded like it was camming the car was warm not cold so i went in the car and the rpm was going down to 450 to 1000 up and down up and down lol like 10 times then it died its popping a little from the exhaust and misfiring .. i recently changed the wires.did the fuel filter.cleaned the maf. spark plugs are about 8 months old but look good .. im thinking iac or vac leak..what do you guys think.and whenever the car is in park then drop to D somtimes it will idle so low like 350 and somtimes it will just die same as reverse. what do you guys think?? thanks.car is stock ..except for a exhaust.but everything is stock..

castine917 · Feb 25, 2012

Common issue for our cars. Follow this links advice. It is most detailed one I know of for fixing the surging idle. http://www.stangnet.com/mustang-forums/threads/help-me-create-the-surging-idle-checklist.698148/

akaslick15 · Mar 5, 2012

ok i got a vid of what it was doing.. this is after the car is warmed up for about 20 mins.and car was in park without touching anything.. has about half a tank of gas any input will help thanks guys

http://www.youtube.com/watch?v=LyFhUTKbpxc&feature=youtu.be

miss2slocoupe · Mar 5, 2012

dam that is weird!!! i wouldnt thought someone was revving my car too LOL i woulda flipped out... hmm all i can say is maybe computer?

ram360 · Mar 5, 2012

It's your IAC. Change that and your good to go.

akaslick15 · Mar 5, 2012

thats what im saying lol thanks guys

akaslick15 · Mar 6, 2012

im wondering if this is causing my trans to tweak on me..its not shifting to 3rd or 4th after 2nd all it does is rev but when the overdrive is off everything is fine..