Hesitation or Stumble getting off idle

[n/a]

My model is 1970, 280sl with Auto trans.
When starting from a stop, cold or warm engine, it nearly stalls completely, stumbles a bit then finally accelerates normally once the engine RPM is between 1000 and 1500.  
After you get through this bad spot it performs well at your chosen speed, in town or on the highway, until you come to a stop again.  
Have replaced most of the normal stuff, plugs, wires, dist cap.  
Whole problem started when Crane 700 went bad, replace original ignition, RPM increased as engine temp increased, replaced Warm-up thermostat, now idle is fine, but still stumbles.
This is a serious problem, it is my wife's car.  
All help greatly appreciated, pretty knowledgable about carburated small block chevy's, but dumb about injected Benz.
Off List contact is welcome.
Klaus Drexl referred me to this group, thanks Klaus.



dave

[Cees Klumper]

Have you checked the usual suspects, like ignition timing & advance / idle fuel mixture / whether the cold start valve on the intake manifold is leaking or not / fuel flow and pressure / fuel filter condition / whether the cold start thermostat closes off completely after warm-up ? It might be any of these things. I'm not totally clear on the Crane part - have you replaced it after it went bad? With what? I had a bad stumble on take-off last summer, turned out to be one of the spark plug wires. This only occurred after the engine warmed up, though. Have you taken out the spark plugs to check their condition?

Cees Klumper in Amsterdam
'69 white 280 SL automatic

[n/a]

Thanks for the comments Cees, I'll be out of town for the comming 2 weeks, but will get back to you when I return with additional info.

dave

dave

[John A. Dean]

My 280SL was doing the exact same thing and was cured with a slight enrichment of the fuel injection settings.  I would be more specific except that my mechanic (who was trained in the 1960's by Mercedes Benz) did the work, and since it was a simpls "turn the adjustment screw" job, he didn't even charge me for it.  Good luck.

1969 280SL, manual, MB TEX, green/cognac