Fuel is extremely flammable, so take extra precautions when working on any part of the fuel system. Do not smoke or allow open flames or lamps without shades near the work area. Do not work in a garage with natural gas equipment with a wick (such as a water heater or clothes dryer). If fuel comes into contact with skin, wash immediately with soap and water. When performing any work on the fuel system, wear safety goggles and have a fire extinguisher ready.
Cold start injector
Examination
The coolant temperature must be below 30°C during this test. It is desirable that the engine was stopped a few hours ago. Disconnect from cold start injector (shown by arrow) electrical connector and move it away from the working area - fuel vapors will appear in the area.
1. Remove the two screws securing the injector to the intake manifold flange and remove the injector. The fuel line remains connected. Wipe the nozzle of the injector. Turn off the ignition system by disconnecting the ignition coil wire from the central contact of the ignition distributor cover and connecting it with a jumper to the cylinder block housing. Turn on the fuel pump for 1 minute by shorting the corresponding relay contacts (see Section Fuel/Fuel Pump Pressure Check). No fuel should come out of the injector nozzle. If fuel comes out of the nozzle, the injector is defective and should be replaced. Switch off the ignition and reset the relay connector.
2. Next, aim the injector nozzle at the jar or bottle. Let the assistant turn on the ignition and starter. Fuel should begin to flow out of the injector into the can. If atomization is good, then the injector is working correctly. If the spray pattern is irregular, the injector is damaged or defective and should be cleaned or replaced.
3. If no fuel comes out of the cold start injector at all, with the starter engaged, check the voltage at the cold start injector electrical connector. If there is no voltage, check the temperature switch.
Temperature switch
1. The temperature switch detects the engine temperature and controls the operation of the cold start injector. Typically, the switch is located at the top front near the coolant temperature sensor. For this test, the coolant temperature must be below 30°C. It is desirable that the engine was stopped a few hours ago. Turn off the ignition system by disconnecting the ignition coil wire from the central contact of the ignition distributor cover and connecting it with a jumper to the cylinder block housing. Slide the rubber cover off the temperature switch and check with a voltmeter for voltage on the connector pin with the black/yellow wire that goes to it.
2. Have an assistant turn on the ignition and starter. The voltmeter should show voltage when the starter is turned on. Voltage should be present for approximately 6 to 10 seconds, depending on engine temperature.
3. If the voltage is correct, disconnect the electrical connector and use an ohmmeter to check for resistance between the temperature switch contacts. It must correspond to a short circuit.
4. Connect the ignition coil wire, start the engine and warm it up to a temperature above 41°C. On a warm engine, there should be no short circuit between the contacts. If so, the switch is faulty and needs to be replaced.
Several types of temperature switches are installed. Each is stamped with operating temperature and maximum on time.
Replacement
Cold start injector
1. Depressurize the fuel system (see Section Relieving pressure in the fuel injection system).
2. Disconnect from an injector of cold start an electric socket.
3. If possible, use a socket wrench or a long socket to unscrew the fuel line fitting attached to the cold start injector. On other models, simply loosen the hose clamp and disconnect the hose from the injector.
4. Turn away bolts of fastening of an injector of cold start and remove an injector.
5. Installation is reverse to removal. Clean the mating surfaces and apply a new gasket.
Temperature switch
Wait until the engine has completely cooled down before starting this procedure. Also, to relieve residual pressure in the cooling system, unscrew the cap of the radiator or expansion tank.
1. Prepare a new temperature switch for installation by applying a thin coat of thread sealant to the threads.
2. Disconnect the electrical connector from the previous switch.
3. Unscrew the switch with a long socket or box wrench. Refrigerant will start leaking after the switch is removed, so install a new switch as soon as possible. Tighten the switch and connect the electrical connector.