I have a 1995 SL2 with 102,000 miles that is not regularly used. After\nit sits for a few days, it won't idle correctly. On cold start, the\nidle settles at 700-750, but as soon as I use the throttle and then\nback off, it will chuff along at 400-500 or, more usually, die. The\nproblem persists after the engine gets to operating temperature - when\nI release the throttle, the RPMs plummet to 400 or death.\n\nHowever, if I nurse the car through a half-hour or so of this, turn it\noff and let it cool completely, then restart within 12-24 hours, it\nidles pretty normally - cold at around 1300, warm at 850, and on\nthrottle release gradually declining to normal idle. It continues this\nduring periods of regular use, but if I let it sit for a few days the\nproblem returns.\n\nI've recently replaced the thermostat, valve cover gasket, plugs and\nwires. There are no lights or codes in evidence.\n\nWhat should I try next?