300d vacuum issues

The shut down problem is being caused by a leak somewhere in the locking system, the task is to find which lock is the site of the leak.

A bad vacuum pump can be rebuilt with a repair kit but if the pump were the problem the car's brakes would be very hard for lack of vacuum boost. That's not the case.

If there were no door lock issue, which is a clear diagnostic aide, there's the possibility that the vacuum bellows inside the injection pump are worn out and need to be replaced, that's for another time, not now.

Update: After trying some troubleshooting recommendations I read in some other threads, I noticed that the passenger side rear door seems to be the last lock up or down. All are slow, but that one really appears to creep. I will test again tomorrow to confirm.

Wondering now...how this is related to the engine not shutting off...I realize that the vacuum system services all components that need it, but in that case, wouldn't the brakes and transmission be failing me now too?

Start by checking for vacuum leaks first, since that's the cheapest. I'm an admitted newbie at this, but I largeley solved a similar problem with my

1985 300SD and actually found SOME acceleration (not a lot) by simply going through and replacing the hoses and clamps. Never hurts to do the easiest and cheapest suff first.

The vacuum pump must be replaced at 200k miles before it has a chance to fail and cause very expensive damage.The fuel shutoff system is failing in your car. Call Rusty at 800-741-5252 for the part discounted. P.