1972 Chevrolet K20 Pickup 5.7L Eng VIN JFACTORY OEM SERVICE PROCEDURE

Time Delay Relay

Time delay relay is a normally closed bi-metallic switch. It is grounded through its housing and completes a circuit from battery through ignition switch or from battery through ignition switch and CEC solenoid, depending upon engine temperature and transmission gear position. Bi-metallic coil opens approximately 20 seconds after ignition key is turned on, providing engine temperature is above 82Β°F, or for approximately 20 seconds after engine temperature switch "cold" override points open. Vacuum to distributor for this time interval improves driveaway and eliminates stall after start tendencies.

Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.

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