1981 240D Mercedes Benz stalling


This wonderful diesel with 257,000 miles and it has been kept in great condition by diligent father. Today as I was driving, it started to lose power in 4th gear. I had to shift down to keep running and not stall. It finally stalled in second gear. Restarted immediately and could only drive in 1st gear or would start to lose power and try to stall. Starts up fine in cold weather. One week ago it did this as well and have not had any problems after that incident but that time it didn’t stall. I have noticed the car sounds louder when driven in the past week or so. I’m not sure what the problem is…


I had a the same problem and come to find out it was the fuel filter. Also the fuel pump that suppies the injectors can be going out.


Yeah, I think it is a failing injection pump. I will probably hear otherwise from the MB diesel fans on the board, but until they get here, my limited knowledge of diesel engines says you are having an injection timing problem.


A bad injection pump is possible, but very unlikely to fail suddenly and then recover. The best bets are either the primary or secondary fuel filter, an air leak in a fuel line (or through the priming pump), a clogged fuel tank strainer, or a clogged fuel tank vent. Start by replacing both fuel filters and take a look at the fuel lines (and primer pump) under the hood for any leaks. If that doesn’t help, try loosening the fuel cap if it does it again. If the fuel cap trick works, you need to look at the little vent valve on top of the fuel tank. Don’t replace the injector pump unless you are very sure, it costs about $1000 (plus labor) and it is rarely the problem.