doesn't want to start in the morning

W123 with 115 engine and Stromberg and Pierberg carburetors use a starting valve to provide additional fuel during warm-up. This device also controls fast idle speed. Starting valve is contained within round housing on side of carburetor. Valve is comprised of a small metal piston that travels vertically to modulate an opening for supplemental fuel. Over time the piston will stick as well as the linkage in the round housing. Remove three screws and round cover to access components, then spray some carb cleaner into housing so as to free up linkage. Piston is below a black rubber boot, so getting carb cleaner in can be difficult. Working the linkage manually to free up mechanism helps. A telltale indication of stuck starting valve is low idle speed when cold, as the fast-idle cam is part of the linkage assembly. Stalling and poor idling when cold also indicate starting valve needs attention. No computers exist on the 115 engines, so AutoZone won't be able to help.