The m103 has a idle switch. If you look closely at the throttle linkage you will find the throttle microswitch. This switch needs to be hit by the linkage when the car is at idle otherwise it will sit at 1500 RPM.

I dont know if thats related to your other problems.

Also inspect your spark plug wires, might be time for new ones too.

I would also get a multimeter and read the duty cycle of the engine, x11 port, on the driver's fender. BOSCH KE3-JETRONIC MIXTURE ADJUSTMENT

If that value is FIXED and not moving after the engine has been running for >1 minute or so..then that is indicating a fault with a sensor or component in the CIS system.

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