How to Use a Vacuum Gauge for Accurate Readings and Better Engine Performance
Connect the vacuum gauge to the engine’s intake manifold and start the engine. Observe the gauge while the engine is idling and see if it’s within the recommended manufacturer’s range. If it’s too high or low, troubleshoot the engine for any mechanical issues that may cause the vacuum problem. For example, a low reading could mean a vacuum leak, while a high reading could indicate a clogged exhaust system. Once the problem is fixed, recalibrate the gauge for future reference.