Horrible surging when cold.....


Active Member
Jul 5, 2003
When warm, the car starts and runs fine. When cold, however, the car will first have an extremely high idle and sometimes surge from almost 0 rpm to 2000 rpm, and it will do thayt for a few minutes. My iac and tps numbers are fine, and the iac motor was just cleaned, any other things i should look into. i also dont think its the MAF but i could be wrong.
mine started doing this a while ago.. when it is completely cold, it revs up and down and runs very rich (smells noxious) for a minute or two. i have been trying to get the basic tuning down and have been replacing some items and changed out the PCV with a new Delco unit and that seems to help a lot. it mostly took care of the off-idle stumble and seemed to help the cold start surging as well. but it still does it for like 10 or 15 seconds before settling on one RPM. :rolleyes: any ideas what might be the root cause of this??
With my car, all that went away when I got a chip from Eric Marshall.
That, and many hours getting the BLMs to behave like they should.
mine never did it until i converted it to a lt1 maf with a translator. now it idles all over the place and i have to foot brake it a little bit when i put it into gear or it will die