I am looking at having the ECM tuned after the 3.1 to 3.4 swap. Are there any recommended changes to the idle speed settings? My ECM ran the 3.1L at about 1,500 cold and 1,000 hot. This is a 5 speed manual trans...

Thanks...

 

Hot idle should be more like 700 I think.

 

Don't touch any of the idle related settings in the bin. There's no need to unless something major has been changed. Your engine has either a vacuum leak or needs the idle relearned or needs the minimum air rate reset. Hot idle should be around 600-700 RPM for a 5-speed as according to GM. Idle speed should be around 1200 RPM cold.

 

Interesting. I have had this car since new (with the 3.1L) and it has always had a hot idle of 1,000 and cold idle about 1,500 (at least as far back as I can remember since I have been driving it for 22 years)... I have done untold number of relearns over the years and replaced the IAC at least 3 times and always the same on the idle speeds resulted.. Vacuum is rock solid at 15 (needle doesn't even twitch) although I expected higher with the complete rebuild of the 3.4L engine that I swapped in... I was just thinking that it might be different with the 3.4L (although I see no particular reason for that to be the case)...