My 1990 Mitsubishi Eclipse (DSM 1G 2L non-turbo) is starts and idles = cold fine, and runs fine warmed up. When warm and I put it in neutral = (AT) the idle oscillates between 1800 and 2200 with about 1/2 second = cycle time.
MAS was the first guess -- so I put a rebuilt mass airflow sensor assy = in and same problem. Checked all the connections and vacuum - all OK. =20
Also took the throttle assy apart and cleaned all - helped the running = but still oscillating. Cleaned Idle air motor, checked voltages and = resistance for all sensors and also voltages coming from the computer, = and all OK.
About out of ideas -- anyone have some thoughts on how to start = troubleshooting this?
Thanks in advance.
Bob