Problem goes like this:
- Rough idle, may stall in wet weather, exhaust smells rich, worse when in gear (Auto trans)
- not noticable when driving (doesn't misfire at speed or under load)
- When MAF sensor disconnected idle smooths out and exhaust leans out (doesn't smell rich)
- no codes in stored computer
- Idle Speed Control motor (Called Motor Position Sensor assy in Mitsu Speak)can be seen adjusting idle when warm causing a surge condition in idle speed (Up/down 300-400 rpm)
here's what I've tried
- Cleaned MAF sensor with fuel injector cleaner
- Tried 2 X MPS assys
- Tried 3 X MAF Sensors
- Tried 2 x ECU computers
- Checked values of following sensors IAW specs in haynes service manual - Throttle Position Sensor - MAF air intake temp sensor - idle position switch - O2 sensor - Motor Position Sensor function and resistance tests
It has also spent a day at the dealer with no results (and no bill luckily) and 3 days at a local "expert" with a $165 bill, a used MAF sensor and a cut MAF power wire to solve the problem (since refunded by garage with apologies for poor work by "expert")
looking for any input on what to try next or where to go to get accurate diagnostic info, wiring diagrams, troubleshooting flow charts, etc (free or at cost, I don't care).
Thanks in advance