Stuck Accelerator

[Iowaner]

I am having an issues on my 1972 250 with the either the throttle or accelerator sticking.

So when in drive the car just takes off sometimes. I don't even have to push on the acceralator and over time can be up to 60!

Any ideas?

[mbbuff]

Iowaner, this should be relatively easy to find and resolve, since all of the throttle linkage is mechanical. Which engine do you have in your 250?

I would disconnect the linkage from the pedal to the carburator(s) at the engine. Actuate the carb. linkage manually looking for any sticking or binding. Make sure the return spring is present and returning the carb. to the idle position. If all is good, hook it back up and move to any linkage bellcrank (on engine or firewall) and disconnect from there to the carb. Now you can check from that point in both directions....to the carb. and to the accelerator pedal. Check for sticking, binding or tightness (dragging, resistance) going both ways.

Let us know which engine you have and what you find.

[Saya]

I have found a couple in my Mercedes Adventures with this issue that leads me to believe it's common. Am I wrong mbbuff?

[mbbuff]

Saya, I don't know for sure, but I've been around vintage Benz's for about 25 years now, and this is the first one I've heard of. Being all mechanical linkage though, I can see where there could be problems with adjustment, rubber/metal bellcranks (like on my M110), and someone along the way tampering with the factory settings. I have replaced the bellcrank on my M110 engine, as it was rotten and coming apart. I can see if it had gone too much longer the linkage could have started dragging on the top of the valve cover, and possibly stick. So many of these vintage MB's have had many owners, and some have had shade tree mechanics work on them too. I feel fortunate that I know the complete history of both of mine.