Prelude L4-1955cc 2000 (1987)
EGR Valve: Testing and Inspection
Carbureted Engine
1. Start engine and allow to idle.
2. Disconnect # 16 vacuum hose from Exhaust Gas Recirculation (EGR) valve and connect a hand vacuum pump to EGR valve.
3. Apply 150 mm Hg (6 in.Hg) vacuum to EGR Valve. Vacuum should remain steady and engine should die.
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If vacuum remains steady and engine dies, EGR valve is working properly. Remove hand vacuum pump and reconnect EGR vacuum hose, test
complete.
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If vacuum does not remain steady and engine does not die, replace EGR valve and retest.
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If vacuum remains steady but engine does not die: Remove EGR valve; check EGR valve and manifold for blockage, clean or replace as
necessary and retest.