Test NTC-14A - Checking Engine Vacuum
WARNING: This page is about a different car, the 1995 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.
Connect a vacuum gauge to engine. Start engine, and let it idle. Normal vacuum reading will vary depending on altitude. Observe vacuum gauge at idle. If vacuum gauge reading is not steady at 13-22 in. Hg, perform TEST NTC-16A. If vacuum gauge reading is steady at 13-22 in. Hg, engine vacuum is normal. Test is complete. Perform TEST VER-2.