Posible dirty throtle body or defective idle air control motor(located on TB).
You can find a vacuum line diagram for a 1993 Plymouth Voyager in the owner's manual. You can also find it at various auto stores.
The blend doors are moved by electric motors on a 1998 Voyager. Vacuum is not used.
There are more than a dozen vacuum hoses in your Chevrolet S 10 pickup truck. The majority of the vacuum hoses are connected to the transmission and the air cleaner. The vacuum hoses are also connected to the fuel injection system.
No vacuum change at the MAP sensor.
find the vacume line and check for a leak in the system
Depends on the vehicle and how it is set up. Some are connected before the throttle plate (ported vacuum or delayed vacuum) and some are connected after the throttle plate (straight manifold vacuum). More info needed.
it will specify under the hood somewhere if it is to be connected or not.
the line is connected to the carburettor if you have one or to the intake manifold after the throttle valve. The purpose is to connect intake vacuum to the booster.
check for unhooked vacuum lines
This must be a vacuum hose, with a connection to the intake manifold, at rear of carb. This must be an after-market distributor because the original "Lean Burn" computer did not have a vacuum advance distrib. The vacuum was connected to the computer that controlled the distrib. advance. these setups, one made by Mopar, kit #P3690426, by passed the computer and is vacuum operated.
It must be connected to a full-time vacuum source such as the intake manifold.
It is a vacuum reservoir. It helps maintain a constant vacuum supply to the HVAC system when engine vacuum is temporarily not sufficient.