DR-20A Checking EGR System

This test must be done with a WARM engine.
1. Connect tachometer to engine, then disconnect vacuum hose from EGR valve.
2. Start engine, then momentarily raise engine speed above 1100 RPM.
3. Allow engine to stabilize for two minutes, then slowly apply vacuum to EGR valve. Engine speed should begin to drop when applied vacuum reaches 2---5 inches and continue to drop as more vacuum is applied. Engine may stall before 5 inches of vacuum is applied.
4. If engine speed drops as described, proceed to Step B.
5. If engine speed does not drop or drops only when 5 inches or more of vacuum is applied, replace EGR valve.