I have a 1987 300E engine number 103.983 or to be more specific 083319. Just recently it is very hard to start, it may take 4-5 times to get it to run. After that it runs great. Could this be a fuel injection problem or the cold start valve? This was a very sudden thing, it went from starting fine to starting poorly over night. I know the fuel pump, filter, and everything related is fine. I was told to pull the spark plugs to see if any are black due to an injector leaking? Just wanted to run it through you guys first. Any help would be greatly appreciated.

 

try to check main relay and fuel pump relay

 

a common problem with the 300 se is a rubber hose
that is located under the air filter.

What I advise you to do is remove the air filter and check if there is any visible damage to several rubber hoses (diameter 20 mm)

After some years the rubber is not so good anymore and then "false"
air will come inside.

In rare occasions one of the rubber will come off a little bit.

Furthermore, recheck all connections like the wires for the sparks
and if necessary replace them with good silicone cables.
It might be possilbe that one of the cables leaks power to earth !!

Also check if the plastic housing around the rotor the "rotor house"
has any little leaks.

Please let us know if your engine is doing better now !

Regards from Holland

Hans

 

Hans.
After tearing apart the engine and checking everything twice found that it was the rubber gas line that comes out of the fuel filter. It was not leaking enough for me to notice in the garage but the minute I took off the splash gard underneath I could see where it was leaking. Thats how you learn I guess.