Won't shut-off... where to start...
 

My '85 300TD has started acting up - periodically (twice now) it won't shutoff and I have to hit the STOP switch under the hood - I know there's a lot of messages on this topic already, and I understand that it's related to the vacuum system, but - where do I start?!

THx,
James

Start by getting a mityvac and determining which subsystem is at fault. For example you can isolate the door locks and the vacuum reservoir at the firewall. Chances are good that the door locks are the culprit. Get familiar with the vacuum diagram for your car for help in tracking the problem down (find which components don't hold vacuum which should).

mine was the line on the drivers side that has a check valve and two major vacuum lines going to it... Couldn't hear it, couldn't see it, wrapped a rubber glove around it, bam shut off. Also, get a mityvac and apply vacuum to the lines running to the back of the INJ PUMP, and see if you shutoff deal is bad.