Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Mercedes Benz >> 1978 >> 280CE >> Repair and Diagnosis >> Engine Performance >> Fuel Delivery >> BOSCH Cis Fuel Injection - MERCEDES-BENZ >> Testing >> Cold Start Valve & THERMO-Time Switch >> 1976 Models

1976 Models

  1. Unplug connectors at mixture regulator and cold start valve. Remove cold start valve with fuel line connected, Point cold start valve down into fuel container.
  2. Turn ignition on. Connect jumper wires from cold start valve to battery terminals. Valve should spray a cone-shaped pattern of fuel. Disconnect jumper wires from valve.
  3. At coolant temperatures below 59°F (15°C), connect voltmeter to cold start valve harness connector and engage starter. Voltmeter should indicate 11 volts for amount of time that thermo-time switch is closed.
  4. At coolant temperatures above 59°F (15°C), switch can be checked with an ohmmeter. Disconnect thermo-time switch plug. Connect test lead to terminal marked "W" in plug (Brown/Black wire) and other lead to ground. See Figure.
  5. Ohmmeter reading should be 270 ohms. If correct, connect test lead to "G" terminal in plug. Ohmmeter should read about 62 ohms. If ohmmeter readings are incorrect, replace thermo-time switch.
scientia non olet · About Mike's Workshop Manuals