i'm working on this myself with a 78 280CE. i believe they share very similar fuel delivery systems.

first, i'd check for vacuum leaks in and around the distributor. don't know if they are similar but mine was leaking, took care of some of the problem.

also check the fuel hoses under the hood and under the car, i found a couple leaky/weepy ones that had to be replaced.

you could also have leaking injectors or a leaking cold start injector/valve. they keep leaking and you have a partially flooded start. or, the thermo time switch could be dead or have a short causing the cold start injector to not work correctly.

do these cars have an air slide valve? what about a warm up regulator, do they have those? these two bosch pieces get wonky over time.

maybe i'm not much help at all...

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1985 300D - 1984 Euro 280E AMG Clone (SOLD) - 1978 280CE (SOLD) - 1983 300D (SOLD) - 1981 300D (SOLD)