I just got my 250sl back from my local mechanic who has had it for about a month. Symptoms are the same as when I took it in and he, in effect, threw in the towel. Here's the situation:
- The engine is slow to start - it takes about 5-10 seconds before it will kick over
- The engine will not idle below 1800rpm; it sputters and dies
- The engine seems to run well above 2000rpm
- The rpm's have started to increase when the brake is pressed (I realize this is almost certainly a leaking brake booster), however the above symptoms existed before this development
Duffelpud,
I too have a 67 250, which I got from from the second owner in Houston, TX a couple of years ago. When I first got the car, the symptoms described in green were exactly the same as I had in my car.
These went away when I changed the electric fuel pump as well as my driving habits... Now, before I start the car from cold and after having it sit for over 1 week, I put the ignition key in the "on" position and let the pump prime the system for about 20/30 seconds before turning to the "start" position. This results in the car starting within no more than two or three turns. There is no issue once the engine is up to temperature, which is when the car starts almost immediately.
Regarding the poor idle, I had myt car tuned up by the local mercedes specialist and it now idles fine. I do believe it does have a bit more room for the fuel injection to be played with, as I can definitely smell the unburnt fuel scent coming out of the back, but the problem has been cured.
Regarding the brake booster issue (highlighted in Blue), I have recently started to notice the same issue. I've started a thread about this thinking there was a chance there may be access to rebuilding it... Have you also noticed lack of braking power in either front ends?
Thanks,
Andres G