Happy New Year to all Tsikoteers!

Yun nga lang, papasok po ang bagong taon ko na may problema . . . and I really need your expert advises.

Mitsubishi Space Wagon, 4G93A engine, A/T. Here are the idling problems:

1. upon starting, OK ang idling. 750rpm A/C OFF at 900rpm A/C ON
2. after 15 minutes, idling soars * 1000rpm A/C OFF at drops * 600rpm A/C ON
3. upon restarting, idle goes back to normal. The cycle repeats on and on.
4. exhaust fumes becomes more noxious over time
5. medyo bumaba ang FC

Thanks in advance!