Having trouble with my 98 1500 in the cold weather. Stop at a traffic light, stall, foot off the gas and on the brake, stall. Any time I lift my foot off the gas it stalls if I don't feather the brake and gas. If I park it doesn't want to start until it finally kicks up the rpm. No codes, no dash lights, nothing. Already replaced the IAC, plugs, wires. Warm weather comes and no problems, only in the cold. Does anyone have any ideas? Thoughts?

 

What brand IAC?

 

Check your vacume line to the power brake unit and the diaphragm. If you have the resources, swap the battery with a known good one -- you do this cuz its easy and don't cost you nothin. I've been running with a the small battery 550CCA that I took out of my Geo Tracker for three months. Nights here are getting into the low 30s and its still working fine. IACs can become temperamental when certain batteries acquire a glitch that isn't always identified by a battery tester. My guess is that something about the batteries make them less able to act as a filter to smooth out the DC level. We've seen the battery as the cause of this a number of times on this forum with the battery testing good on a battery tester. This isn't a guess that justifies going out and buying a new battery. Just swap it out of another car to see if it fixes it.