by turnturn » Tue Sep 15, 2015 8:45 pm
From memory there are only two or three things that use vacuum in a 92.
1) Brake booster, big hose from vacuum pump to brake booster. This is a neccesity.
There is a vacuum supply line (smaller, about 6-8mm diameter) that runs from your vacuum pump over to a couple of actuators mounted on the passenger side inner guard. These actuators trigger -
2) Fast idle for air conditioning (part of your Injector Pump). Handy if you use the air conditioning a lot in city driving.
3) Exhaust Gas Reticulation (EGR) valves on your intake manifold. This can be removed/disabled.
4) Quick Warm-up System (QWS) is two vacuum operated butterfly valves. One in your intake system and one in your exhaust system. The actuators for these two may be on the drivers side inner guard. These can be removed/disabled. On the 2.8 the exhaust butterfly valve is part of the exhaust manifold. On your 3.1 donor motor it was probably about under the drivers seat.
Also be aware that there is another hose that looks very similar to a vacuum hose but is actually a boost hose. It goes from your intake system (post turbocharger) to the Boost Compensator that is part of your Injector Pump.