2.8 V6 High Idle on Startup (Page 1/1) T Top 88 FEB 06, 04:04 PM Hi all, recently noticed an issue (I think) with my 88GT's cold idle. Currently on startup, the car will go to the correct 1500RPM for about 2-3 seconds, then shoot up to 1600-1800RPM (varies from time to time). After a minute or two it will drop from the high idle back down to 1500RPM and is normal once warmed up (idles at 925-950RPM) the only unusual thing I notice is an occasional spike at idle from normal speed up to 1000-1050RPM. I've tested for vacuum leaks, as I know that can be a common problem. I've replaced all the rubber lines, and all of the hard lines check out with a vacuum pump. Has anyone else had this issue? My only other thought is it possibly having to do with the cold weather (0-35 degrees Fahrenheit). TIA! (1988 GT 5MT) ArthurPeale FEB 06, 04:11 PM None of that seems particularly out of line, for the first few minutes of operation. Possible reasons are vacuum leak you haven't found, EGR leakage.... 82-T/A [At Work] FEB 08, 12:02 PM quote Originally posted by T Top 88: Hi all, recently noticed an issue (I think) with my 88GT's cold idle. Currently on startup, the car will go to the correct 1500RPM for about 2-3 seconds, then shoot up to 1600-1800RPM (varies from time to time). After a minute or two it will drop from the high idle back down to 1500RPM and is normal once warmed up (idles at 925-950RPM) the only unusual thing I notice is an occasional spike at idle from normal speed up to 1000-1050RPM. I've tested for vacuum leaks, as I know that can be a common problem. I've replaced all the rubber lines, and all of the hard lines check out with a vacuum pump. Has anyone else had this issue? My only other thought is it possibly having to do with the cold weather (0-35 degrees Fahrenheit). TIA! (1988 GT 5MT) Do you have a check engine light on? If so, the first thing I would do would be to check your codes. You can do that by going here: https://www.pontiacperforma...icles/OSG/codes.html Other than this, my first thought is a cracked EGR tube (goes between the underside of the intake just behind the throttle body, to the EGR valve)... or even a failed EGR valve. 1,000 rpms is still not really normal. ~850 rpms was always more normal to me when fully warmed up.