NO vaccuum from VCV? (flaring issue)

[pleiades]

The car below is a 1982 300CD (turbo). Federal car, as far as I can tell.

Transmission has been flaring, so I ordered a mityvac. Note that I have already disconnected the EGR, blocking the vacuum lines going to it where they originate.

As I understand, the off white thing sitting on top of the IP (with two lines out, one with a green inline thing) is the VCV - Vacuum Control Valve. This Ts into a 5-way connector, with lines going several directions, to the EGR, to supply, to the transmission.

I disconnected the line from the supply (furthest from the firewall) and attached the mityvac. It pumped up to only about 14"Hg, and slowly leaked down.

From reading other posts, I took that this was a leak at the modulator (green thing?) so I reconnected the supply line, and disconnected the line from the green inline device and plugged the mityvac into the device. Turning the car on, I expected some vacuum, but none (zero) was produced. Pumping up the mityvac, it went as high as 14"Hg and would hold there, with no leak.

I'm pretty sure the vacuum pump is working, because the door/trunk locks have been working perfectly ever since I got the car. Is this an indication that the VCV/Modulator (I'm not sure what the distinction is) is producing NO vacuum at all?

[MattBelliveau]

I think you are a bit confused about the work that these parts do. Neither actually "produce" vacuum, they either hold it (pressurize it), or reduce what is already in the system (being the case of the VCV). Does the inline "green thing" that you tested close to the VCV (sits on the IP)? If so, that's not the modulator. That's a check valve. Treat this piece as something different from the VCV for testing reasons, and remove it. Put a finger over one end, and try to pull a vacuum (with your mity-vac). If it doesn't leak, its fine (which is probably true.). Next, connect your vac pump to the VCV itself (you should connect to the top of it). With the car off, pull vac. If it holds (which it should, if it doesn't, replace it), operate the accelerator linkage from beneath the hood. This should be connected to that VCV. You vac should leak down to 0 in ration to throttle movement (ie, idle = 12-14hg, full throttle (all the way open) = 0). The VCC is adjustable, but be VERY careful. For easy confirmation of working VCV (might want to try this before getting under the hood with your mity-vac), try this: Star the car, put it in gear. From a stop, push very lightly on the accelorator (just enough to make the car go and shift), and look for normal shifting (even harsh shifts would be OK at this point). Then, give it almost full throttle. If is flares, then the VCV is at fault. If you need additional help, PM me with a phone number. My transmission vac is dead on, which definately wasn't the case when I first bought it. Ive troubleshooted and perfected everything myself. Good luck.