The 1988 Chevy Corsica air conditioning service valves can be found on top of the air conditioning compressor. The air conditioning service valves are labeled as the low pressure valve and the high pressure valve.
That is a VENT valve hose, so the rear end don't build pressure in it. Any rubber hose will work in it's place.
Assuming V8 gasoline engine, it should be bolted onto the intake manifold.
either bad gasket under throttle body or bad iac valve
Low pressure valve.
It is in the top of the valve cover. It has a black plastic line coming from the throttle body housing and going into one of the valve covers. It will be stuck in the end of the line and down into the valve cover.
That would be the low pressure service port and it should be located on the receiver/dryer.
It's located inside the low and high pressure service ports. They tend to wear out and leak
The low pressure valve on a 93 Chevy Corsica is under the hood. It is on the larger hose coming off the AC air compressor.
I would be suprised if you have adjustable valves.
The egr valve is on the top of the engine in the front it is plugged into your wiring harness and has two bolts holding it on, it is shaped like a cylinder and is next to the water jacket on the engine.
On my retrofitted to R134-A the fill valve is underneath the airbox. You have to take it out to get to it.