She just keeps on running after I take out the key. I have checked all the vacuum lines, they are ok. Is there a shut off solenoid in the mass of plumbing, somwhere?

One easy way to TOTALLY rule out the vacuum system is to lock the front door lock. If the engine shuts off with the front door locked, then it is probably in the vacuum system.

For further diagnosis, I'll let the experts chime in.

JCD

Run a search through previous threads under "vacuum". I did this when troubleshooting and had about 20 pages printed off. There is some great advice there.

Don

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Slydel:

On the back of the injection pump there is a vacuum servo -- has a brown with blue stripe vacuum line going to it.

This is the shutoff. There is a red square-ended lever that says "STOP" that you push down (hard on the 617 engine) to shut the engine off.

There are three possiblities here, listed in usual order of occurance:

A vacuum leak on the brown or brown with blue stripe line, most often a bad rubber connector -- the hard plastic lines are usually OK. They get brittle, though, so may be broken.

The vacuum servo won't hold vacuum anymore -- test by pushing down the lever with the vacuum line off, cover the vacuum fitting, and see if the lever comes back up. If it doesn't stay down as long as you have your finger over the fitting, it is shot.

Ignition switch vacuum switch is bad and isn't providing vaccuum to the cutoff. You can check by pulling the line off the servo, then shut key off and check for vacuum at the line.

You can also use a MityVac pump (much easier!) to check the lines and switch. The servo should pull the lever down with one or two pumps -- if not, the diaphram has a hole in it.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Try this thread, Icesailor has a pretty good logical approach 82 300TD A/C problem

Ernie

Icesailor where are you?

Thanks for the help, I am just starting to understand this complex system, I will check all as suggested. I noticed that if I shook the key yesterday, it shut down!!!! This suggests the switch.