123 engine shutoff problem
 

While doing a purge on my 85 300TD, I inadvertently broke off one of the plastic vacuum tubes that come off the large tube connecting the Vacuum pump with the power brake thing. I have replaced this and checked every single tube under the hood, and still, the engine will not shut off.

In the past, I have always been able to find the lose tube, but this time it is baffling.

What tube shuts the engine off, by the way? I have a MityVac and plan to attack this again soon. The diagram printed for California 85 TD's does not seem to resemble my car.

Many thanks.

You may have pulled the line off your shut off valve on engine. It looks like thishttp://img.eautopartscatalog.com/hir...300&height=300

Pretty easy to locate too. On my '83, there are two vacuum lines heading down the left rear side of the engine. One goes down past the engine to the transmission. The other goes to the engine shutoff, mounted at the rear of the injector pump. If this one is off, my car would not shut off, except with the manual shutoff lever.

The brown line runs into the cabin to the ign and then back out to that shutoff solenoid. With everything else plugged off this should work. More than likely you have something going to the wrong place (like the ALDA->ARV which looks like vac but is really boost).

you have a vacuum leak, the vacuum part of the ignition switch may be bad, the vacuum dashport attachd to the injector pump may be bad or something is misrouted. Use a hand vacuum pump to find a vacuum leak

i have this same problem with the 77 and will deal with it soon

Something must be loose, probably in that octopus of lines near the yellow check valve coming off the plastic tee that broke.


This is a basic diagram of the vacuum shutoff circuit. "A" is the firewall. If everything is hooked up correctly, it should work.

http://home.comcast.net/%7Ephantoms/...IP_shutoff.jpg

If that is all hooked up right, you might have a leak somewhere in the system, check out said octopus for loose lines and lines not connected, this is the fun part :D (utter sarcasm)

Yup. I've seen this before. It starts off as a vacuum leak, then the motor won't shut off. Soon after, the motor blows up. I'll take it off your hands before it happens, saving both of us money in the long run.