Engine Mechanical problem
1999 Other Mazda Models 4 cyl Two Wheel Drive Manual 148000 miles
Daily with stop and go traffic, while shifting gears the idle increases. Shifting at 2k rpms the engine will increase to 2.5k or higher and hold. Will not decrease. Have had to turn off the engine to get the rpms to come down.
Seems to increase frequency with high air temps.
There is an idle speed control module, a TPS, and the module resets these when you switch the key off. Have someone scan your diagnostic connector for codes that help a tech. Find out what the problem is, as loads increase and decrese, air flows change. The air flow sensor may be bad, depending on the model. Ok, There may be a computer fault code. Idle speeds are sort of a controlled vacuum leak and a motor(small) is used to determine all engine speeds off idle.