91 350 sdl, won't shut off, and wont shift on hills. Obviously a vacuum problem right? So I went ahead and purchased the mighty vac, and when it came without a gauge purchased a gauge. I guess here is my question, I have tested the line that goes to the egr vacuum transducer, it makes a plastic type clicking noise at the transducer and does not hold vacuum, however when this line is plugged vehicle will not shut off. Also line that runs into manifold holds no pressure, just replaced manifold so their may be a leak in that but their is a huge amount of volume their so I don't think that's the problem. Also Y from aneroid compensator does not hold vacuum, yet again when isolated car does not turn off. So I guess my question is where should a guy start with vacuum diagnosis and then progress to, and what lines should hold vacuum and which not? I thought it would be a bit more straightforward, just find the leak and fix, but ??? Is their anywhere to go where someone has outlined this process before?

Take a systematic approach to the mess.
Isolate passenger side vacuum devices by plugging the 2 ports that feed those things at the 5 port (4 port for Federal car) connector above the vacuum pump.
You should then have no vacuum connected to the mess of emission control garbage on the passenger side (save for a black fresh air line on a transducer).
You should then be left with 2 vacuum lines on the 5 port (4 port for Federal car) connector feeding various items on the drivers side of the engine including the switchover valves , trans amp., trans vacuum control valve.. etc....
Check the vacuum again where you want to on the drivers side to see
if your leak was amongst the garbage on the passenger side emission control devices.
If you still have problems take a look at this post - there are some vacuum diagrams listed.-

http://www.peachparts.com/shopforum/showpost.php?p=1711467

Follow those to track down you problem.
Could be a number of leaky devices if on the drivers side in the things that actually do something of value.

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1986 300SDL 201K Daily Driver
1984 300D In Progress
1989 240GL 196K Swedish Brick
1984 300SD -- Sold 289K
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