My 300E is hard to start the first time each day. The engine spins normally and it tries to start 2-3 times. Once it starts, it kicks right off for the rest of the day. Is my cold start valve defective?

Walraven, more than that
 

I must have overlooked what year your 300E is. For your cold start enrichment system to operate, it must know it is cold. This info comes from the engine temp sensor. I have a '87 W124030 and if your is close to the same, I may be able to tell you where that rascal lives and his home address. Happy Trails Beep Beep from Houston.

Donald
your little ole postman

The cold start valve (injector) sits on a little mini manifold between the fore and aft runners of the intake manifold (in the middle, three runners in front and three runners in back. It looks like a fuel injector, which it is. Usually pretty reliable. Controlled by Temp sensor and thermo valve. Check the tubing it sits on. It is plastic, gets very brittle and is known to break.

Check it Out
 

Walraven, Jeffsr told you where it all is and gave you some very valuable hints. You should consider finding a set of Shop manuals, if that is possible or a CD for your model. Happy Trails Beep Beep from Houston.

Donald
how about Jeffsr's response time?

300E HARD TO START WHEN COLD
 

Sorry! It is a 1988 model.

Have No Fear
 

Walraven, 1986-1990 are the same in this cold start area. Check the items suggested and get to the source of your problem. Happy Trails Beep Beep from Houston.

Donald
a warm shoulder

I have the same proublem with my 1989 300E, but seems a bit different due to the fact that this does not happen every time I start it cold, and sometimes when it does happen 5 seconds or so into it running rough it just picks up idle like the choke or something starts working. DOes not happen all the time though, maybe every 3rd or fourth day.

all 300es had ovp issues.if the relay is not working or the fuse is blown in the top,the car will try to start in limp mode[no power to the ecm].once started and warmed it would run rest of day although with only 75% power.

What is the ovp and where is this fuse and the relay? Thanks.