91 galant idle probs

[quickbrick]

i got a 91 galant and it wants to idle up and down in drive. it doesnt do it all the time. i looked at the iac and its pushing the throttle in and out at idle. ive had the ecu rebuilt when i bought it cause the car would not start. now it starts and runs good except the idle. does anyone know how to check the iac or reset it? im trying to figure out if the cpu is making the iac push the throttle, or if its a defective iac. thanks in advance

 

[Randy Greenoe]

Is it a 2.0? On the Talons there is an idle screw under a rubber plug on top of the throttle body. On this screw there is a small O-ring Check the O-ring Once I ran into the same problem you are having and all I did was put a new O-ring on and a little lubricant on the screw and it cured the problem. H.T.H.

 

[TurboJim]

Originally posted by quickbrick
i got a 91 galant and it wants to idle up and down in drive. it doesnt do it all the time. i looked at the iac and its pushing the throttle in and out at idle. ive had the ecu rebuilt when i bought it cause the car would not start. now it starts and runs good except the idle. does anyone know how to check the iac or reset it? im trying to figure out if the cpu is making the iac push the throttle, or if its a defective iac. thanks in advance

Clean the throttle body, just like in the GN. Otherwise, take it somewhere to see if it has any codes stored. While the guy is connected, verify the MAF is reading correct elevation, very common for the mitsu MAF's so go off kilter and read barometric pressure wrong

 

[quickbrick]

i didnt see a screw on the throttlebody. that might be dohc only. i turned the idle screw one turn and it seems to idle ok for now. ive cleaned the throttle plate recently. if it continues i will have them hook it up to a diagnostic machine. thanks

 

[Mustang1969]

Thanks to the fact that DSM's need a plethora of mechanical information, they have this for you:

http://www.dsm.org/how-tos/tttt/tttt3.html