I have what I think is a strange problem. I'm trying to figure out what it is.. does this sound familiar?

here is what happens:
I start the car cold, and it starts up fine, runs very well, drives very well.
I turn the car off, and the car refuses to restart for about 20+ minutes.

even after waiting, I have to turn the distributor to advance the timing quite a bit to get it to catch.

any ideas what could cause this?

I have checked my point gap, it seems OK. once the car is running again, all seems to be well (as long as I change the timing back to normal).

same issue in this thread

http://www.peachparts.com/shopforum/vintage-mercedes/367803-1972-280se-4-5-running-rough-stumbling-when-hot.html

__________________
W211 '03 E320 | W108 '72 280SEL 4.5

http://i66.photobucket.com/albums/h2...ps9b542eaa.jpg http://i66.photobucket.com/albums/h2...ps5723c50f.jpg

thanks! I read through that thread, and others like it. I will continue to track down the basics in a more methodical manner.

Hello,

I have a 250SL with the same engine. On the back of the injection pump, there's a Starting Solenoid that slightly enriches the mixture when starting the car. Turning the ignition switch to START sends a signal to a relay under the hood, which activates the solenoid. A lever inside the injection pump is either pushed or pulled (can't remember) and this makes the mixture more rich while trying to start the car (it aids in starting a warmed up engine).

When I first got my SL 10 years ago, this solenoid wasn't engaging. I opened the relay and cleaned the contacts. Plus I had to slightly bend the relay arm so it would make contact easier.

While I can't imagine this causing such a problem, it can certainly contribute.

JA17 is an expert on these cars (Joe Alexander). You can also post your question under Home - Mercedes Benz 230SL, 250SL, 280SL Pagoda Group in the W111 section (in the forum). This will be another source of information. See the following article for an example of poor warm running (I know yours just has trouble starting but you can see the level of expertize Joe has):

280 SE runs poor when warm | Mercedes-Benz Club of America

Here's another article which discusses warm starting problems....I even jumped in on this one back in 2006:

http://www.sl113.org/forums/index.php?topic=5469.0

__________________
All the best,

J. P. Mose
1968 250SL
1970 280SE 3.5 Cabrio
1987 560SL
1990 560SEL

The cold start valve on the intake has a wire going to it. Try a jumper wire from the battery, touch the csv wire a couple times with key on. It should give it a shot of gas. If that works run a wire from starter solenoid to the csv.

Also check gas cap for venting. A plugged vent could suck the gas back into the tank.

I have seen this before and it was usually a worn timing chain. This throws off your valve timing and pushing the ignition timing up is the only way to get it to start. This is not just on FI engines but carbed ones, too.

But it will not run well that way, so then it must be corrected back to spec.

It might not hurt to have your valve timing checked by a Mercedes mechanic with a good reputation. This is not for the average mechanic to dive into. This may be one of the rare times a trip to the stealership might be called for.

It's cranking normally when hot?

__________________
___
/<>/>/>
1967 230S automatic
Boston, MA