Mechanical Inspection: Vacuum

WARNING: This page is about a different car, the 2003 Suzuki XL-7, 2003 Suzuki Vitara, 2003 Suzuki Grand Vitara, and 2003 Suzuki Aerio. However, it is still accessible from the selected car via links, so may be relevant.

Engine vacuum that is developed in intake line is a good indicator of engine condition. Perform engine vacuum check as follow:

Set transmission shifter lever in "Neutral" position ("P" range for A/T model), set parking brake and block drive wheels. Start engine and allow it to reach normal operating temperature. Ensure that engine idle speed is within specification. See IDLE SPEED & MIXTURE in ON-VEHICLE ADJUSTMENT article.
Turn ignition switch to LOCK position. Disconnect vacuum hose and connect vacuum gauge and 3-way joint hose between vacuum hose and intake manifold (Aerio and Vitara). See Fig 1 . Disconnect vacuum hose and connect vacuum gauge and 3-way joint hose between vacuum hose and fuel pressure regulator valve (Grand Vitara and XL-7). See Fig 1 .
Start engine and let it idle. Read vacuum gauge, vacuum should be within specification. See VACUUM SPECIFICATION table. If vacuum is not as specified, check engine compression. See COMPRESSION . Also check exhaust backpressure. See EXHAUST SYSTEM BACKPRESSURE .

Fig 1: Installing Vacuum Gauge

Courtesy of SUZUKI OF AMERICA CORP.

VACUUM SPECIFICATION

Application	Specification
Aerio & Vitara	15.7-19.7 in. Hg (40-50 cmHg)
Grand Vitara & XL-7	17.7-23.7 in. Hg (45-60 cmHg)