The only L-jet, MB ever used, was the LH used in 119 v8s and the first year (1992) electronic 104 injection.

What most 110 engine have is K-jet, with some US models having K-jet w/lambda. I presume what you are calling a WUC is the control pressure regulator. This has nothing to do with engine speed. It is used the vary the mixture for warm up and sudden acceleration. What you do need most likely is a new auxilary air valve. This valve has a wax bulb in it just like the thermostat that warms the motor. As the engine warms the bulb expands and opens the valve in a thermostat. In the aux air valve, as it expands, the airslide closes and the extra air needed for cold running is shut down.

Remember that engine speed is determined by the amount of air entering, not the amount of fuel. Any way that extra air gets in the motor will cause it to run faster. If you have the idle screw all the way in you either have vacuum leaks, a throttle that isn't closed, a bad aux air valve or too much timing or a combination of all of the above.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician