'81 240D running rough and vibrating at low speeds and stopped
 

Hello, all.

If anyone could provide some assistance as to what the following problem could be, it would greatly be appreciated.

About a week ago, I noticed that my 240D began to vibrate badly at speeds of 25 MPH and below and continued even worse while the vehicle was completely stopped. The vibration is somewhat reduced when I turn the manual choke all the way to the left stop, but the vibration is still very noticeable.Turn the choke all the way to the left is the only way I can get the vibration down to a manageable level and to prevent the car from shutting off.

If I would move the choke back to the normal operating position, the car vibrates very, very badly and threatens to cut off. The only way I can describe the vibration is almost like it is hitting on only 3 cylinders instead of 4.

When I accelerate, the vibration goes away, though at cruising speeds it seems the engine is running a bit rough.

I was thinking it might be the injectors or maybe the fuel pump. The car has 219,000 miles on it and both items are original. Any help to keep me away from the MB dealer would be greatly appreciated.

Thanks,

Steve in Charlotte, NC