Idles fine but stalls at 1.500 RPM

[Geram Brick]

my B230F starts fine and run smothly idle speed. When opening the trottle the engins does not turn more than 1.500 RPM. I have cleaned the trottle and have ex changed the TPS and adjusted it by the click-click method. Running the fault testing it shows 2-2-3 no signal from idle control valve. Checking the ignition system I got the 2-3-4 fault - Trottle Switch (idling) faulty. Engine running with savety retarded ignition (10°). This fault code could be reseted. Doing functional testing the operation of the idling switch and speed sensor could be confirmed. Doing the function testing of the fuel system the the code 3-3-2 confirming the the operation of the idling switch could not be confirmed.

What could be the problem and what else clould be checked?

Thanks, York