Chery QQ3 2009, 0.8L engine with a weird control of aceleration

The vehicle just had engine work done because one of the three cylinders had almost no compression. The throttle body and the IAC valve were cleaned. It was only showing codes related to the temperature sensor, so the idle couldn’t be programmed. I fixed the temperature sensor wiring, and after performing the IAC programming, the idle now holds steady at 900 RPM. When I rev it quickly, it responds well, but if I keep it revved for a few seconds, the RPM gets stuck above 2000 after releasing the pedal.

The live data for the TPS reads correctly. It feels like the IAC sometimes gets stuck, but I'm not sure whether the live data I'm seeing for the IAC reflects its actual position or the position the ECU wants it to be in.

David,
I am not familiar with that engine, but IAC data PID typically reflects the desired or commanded position of the IAC valve, not the actual position.
I agree with your suspicion that it may be getting stuck keeping the idle high.

 

Both are the same, comand  and posición.

The IAC has already changed by the costumer a month ago. When I disconnect the TPS, the engine immediately revs up, I would think the ECU enter in a mode that it's just using the MAP sensor to see engine charge. However, if I disconnect the MAP sensor and leave the TPS connected, the car continues to run fine and doesn't get stuck above 2000 RPM after accelerating. This makes me think the MAP sensor is out of range. The voltage with the engine off is 4.1V, and the scanner also shows 4.1V. The scanner reads a pressure of 9.6 PSI, which is very low for here in El Salvador, since we are almost at sea level.