Vacuum problem 85 300TD won't shut off

[Richard Eldridge]

Prior to doing a purge on my 85 3oTD, the car shut off every time and the door locks would hold pressure for about fifteen minutes. The leak is in the passenger front door, and I was planning to fix it.

I ran a can and a half of Lubra Moly and changed the air filter. When I finished, the engine would not shut off, because I had inadvertently broken the two nozzles off the metal tube that runs from the Vacuum Pump to the power brakes. I replaced this, and reconnected the tubes and still it would not shut off. I have determined that I have a vacuum in the line I replaced, a steady 20 lbs. I can also shut off the engine by sucking with the mity Vac on the shutoff valve line. What I can't do is to shut off the engine in any way other than sucking on that line wioth the MityVac or pushing the off lever under the hood. The door locks do not work, either.

I tried pushing a golf tee in the yellowish device that connects two yellow tubes to one that I think controls the door locks, to remove these from the problem, as someone suggested in another post. I have also tried connecting a line from the vacuum pump line directly to the shutoff valve, None of this works. The diagram given for a 1986 California model does not resemble my car. Above the shutoff valve, which is metal and invisible from topside, is a white plastic thing with two tubes coming out of it, one goes to a four-outlet connector that connects to the vacuum pump line.

The other line off the vacuum pump goes to a triple connector. Both of the lines off the vacuum pump have a steady 20 lbs. vacuum with the motor running, and these were the only ones I found disconnected.

The shutoff switch connects to a brown and blue line that goes into the firewall. There is a lot of play in this line, but it is connected to something inside.

I have had similar problems before, and when I did, I replaced all the lines that appeared deteriorated or cracked, one by one, once I got it running.

I have spent about three hours on this so far. I normally get everything up and running within a half hour, but this time I am stumped It seems pretty certain that the problem is a tube that is disconnected that I cannot see, or a tube that is connected to the wrong place. I appreciate any help anyone might offer.

I have not removed or swapped more than one pair of lines at a time.