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1977 924 Models

  1. Remove EGR valve from engine. Apply vacuum to valve and observe that valve stem lifts off seat. If not, replace EGR valve.
  2. Coolant switch should remain closed at coolant temperatures below 140°F (60°C). No vacuum should be allowed to flow to EGR valve. The EGR valve should remain closed and EGR system should not operate.
  3. With coolant temperatures above 140°F (60°C), temperature switch should open. This should allow EGR valve to open if vacuum is high enough. The EGR valve should remain closed during full throttle and idle.
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