EGR System Check

Run engine with engine temperature below 131°F (55°C). Ensure that EGR valve diaphragm does not operate. Warm engine to normal operating temperature. Increase engine RPM.
Diaphragm should move away from piston side of EGR valve during acceleration. Decelerate engine and check that diaphragm moves toward piston side of EGR valve. See Fig 2 .

Fig 1: Exhaust Gas Recirculation System
Courtesy of SUZUKI OF AMERICA CORP.

Fig 2: Testing EGR Valve Operation
Courtesy of SUZUKI OF AMERICA CORP.
If EGR valve does not function properly, check vacuum hoses for defect. Check EGR valve by attaching vacuum pump to EGR hose at TWSV. See Fig 2 . Apply 8 in. Hg to EGR valve and check that diaphragm moves smoothly and is held toward vacuum pump side.
If EGR valve does not operate properly, replace valve. If EGR valve operates properly, check HAC, 5th gear switch and their circuits. See CARBURETOR FBC SYSTEM article in the COMPUTERIZED ENGINE CONTROLS section.