massive vacuum leak???

Hi all,
Trying to pin down a vacuum leak on an 82 380 SEL and could use some help. Using the Miti-vac, I can see most of the system holds vacuum pretty well. I pulled the 4 way tee off the Intake Manifold and pulled
20 hg and it held pretty good...a very sloooowww leak, but not enough I would think that makes the car undrivable.
However, when I tested the big black line off the charcoal canister going to the Throttle Valve Housing I couldn't get a reading. Went to manual mode (mouth) and was able to push and pull air throught it pretty easily and could hear the air whistling in the air guide housing. Did the same thing on the line from the distributor to the Throttle Vavle housing (white/red line) and got the same result...no vacuum or pressure response but could hear the air moving in the housing. Should these two lines normally be able to hold vacuum? Could the Throttle Vavle Switch be a culprit?
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Did the same thing on the line from the distributor to the | Throttle Vavle housing (white/red line) and got the same result...no | vacuum or pressure response but could hear the air moving in the | housing.
the vacuum advance connection on the engine is just before the throttle valve and after the cis airflow meter. Its not going to hold vacuum. If you're sucking the other direction, i.e. the vacuum advance diaphragm, then it should be able to hold vacuum, and if it isn't, replace it.
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thanks for the input...tried the other direction, and the adv diaphragm did hold vacuum. But atleast I know I can move on to the next item.
When the car is idling, I get a real bouncy reading of 5-10in Hg. The jitterry reading my be from worn valve guides (or other), but the reading is still really low. The engine bogs down when I give it gas, but when I pull the throttle and push on the air plate the engine revs just fine. I read somewhere that this is because there isn't enough vacuum to pull down on the plate. I'll test the injector seals again with carb cleaner but any other ideas?
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What is your timing set at????

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You should also check the valve timing. it may have jumped a cog. I had similar low vacuum symptoms on another car sometime back. Peter

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