95 SC1 idle fluctuates

i have a 1995 saturn 4 dr sc1 1.9 sohc 5 spd with approx 260,000 miles.the car has been meticulously maintained.still runs great and still get 34 mpg on the hiway.my problem is this. when car is start cold or warm rpms fluctuate from 500 to about 1500.sometimes idles perfectly normal.also at times when clutching to stop,idle will drop to 0 and car will die.starts right back up.not a sreious problem,but an annoying problem.i have checked all elec connections to sensors on throttle body,cleaned t-body,cleaned pcv valve checked map sensor? opposit end of intake from t-body.also checked all vacumn lines i could find for possible leaks.found none.any ideas would be appreciated.