No such part exists on a Durango.
It doesn't have one its electronic
Need to know which one you are looking for or, what does this vacuum control valve control.
'vacuum control module'
There is no ignition module on a 1987 5th ave. The spark control computer is on the air cleaner with a vacuum line hooked to it.
You don't. The ECM (Engine Control Module) maintains the correct idle speed. If the idle is out of control you probably have a vacuum leak.
Check the vacuum hose that feeds into the cruise module in the engine.
The EGR (Exhaust Gas Recirculation) valve opens when vacuum is applied. The EGR vacuum solenoid opens and closes the vacuum supply to the EGR valve when it is commanded to do so by the ECM (Engine Control Module).
The 2001 Chevy Impala vacuum module can be found on the back of the engine. The vacuum module valve will be near the top of the engine.
The CC system on a Vanagon is vacuum actuated; overly complex and thus failure prone IMHO. For fault you describe I'd start by replacing the CC control module; located (on my '91 Westy) behind the glove box (as in remove the glove box to get to it). There's only a few components to the CC system; the vacuum pump (engine compartment); the control module (indicated above); and the vacuum breaker switch (under the brake pedal). Vacuum pump and/or vacuum breaker switch failure (to include hoses) will result in decrease in speed or inability to set at all (won't hold a vacuum); continuing to accelerate could be caused by faulty control module. Bentley (factory) manual has good fault logic tree for troubleshooting system; somebody might have posted same to internet. Suggest Bus Depot or Go Westy for best internet parts prices (w/quality). Good luck!
If the cruise control system fails to power on, i.e. the light on the cruise control switch does not light, check the fuse. If the fuse is not blown, there may be a problem with the wiring or the cruise control module itself. If the system powers on but it fails to keep the vehicle at speed when engaged, the vacuum hose between the cruise control module and the actuator may be faulty. The cruise control module can be found at the rear of the engine compartment near the driver's side door. A black vacuum hose runs from the module to the actuator, which is a round black plastic object which is connected with a cable to the throttle. Disconnect the vacuum hose from the actuator and inspect the end. If it is cracked, you may be able to cut 1/4" from the end of the hose and reconnect it.
rear drivers side of tranny,likely a 700-r4 trans
How to replace the inside Spectra Heater Core on a 2000 dodge durango??