XJS Cold Start System Test

Remove 2 set screws and washers retaining cold start injectors in intake manifold. Remove the start injectors and place them in a container to collect sprayed fuel. Disconnect distributor lead from the coil.

Engine Temperature Below 59°F (15°C)

1. Turn ignition on and check the cold start injectors for any leakage. Crank the engine for a few revolutions. Injectors should spray while engine cranks. DO NOT  operate starter any longer than necessary.
2. If injectors do not spray, crank engine and check for battery voltage at cold start injector supply (White/Pink) cable. If voltage is present, check ground connections and wiring harness connectors at cold start injectors. Repair as necessary. If no defects are found, injectors are faulty and must be replaced.
3. Crank engine and check for battery voltage at terminal No. 87 of cold start relay. If voltage is present, check wiring harness between relay and cold start injectors and repair as necessary.
4. Crank engine and check for battery voltage at terminal No. 30 of cold start relay. If no voltage is present, check supply wire from pump relay and repair as necessary. If voltage is present, relay is not being energized or contacts are faulty.
5. Crank engine and check for battery voltage at terminal No. 86 of cold start relay. If voltage is present, relay is not being energized or contacts are faulty. If no voltage, repair supply wire from starter circuit.
6. Crank engine and check for battery voltage at terminal No. 85 of cold start relay. If voltage is present and relay is not energizing, there is a problem with thermo time switch circuit. Disconnect wiring harness from terminal No. 85 and jump terminal No. 85 to ground. Relay should now energize. If not, relay is faulty and must be replaced.
7. If relay energizes, check for battery voltage at terminal No. 87 of cold start relay. If no voltage is present at terminal No. 87, the contacts of relay are faulty and relay must be replaced. Reinstall cold start injectors and all cables or connectors.

Engine Temperature Above 59°F (15°C)

1. Crank engine and check voltage at terminal No. 87 of cold start relay. Voltage should be 0 (zero) volts. If battery voltage is present, remove wiring harness connector from terminal No. 85 of the cold start relay.
2. If voltage is 0 (zero) volts, the thermo time switch is at fault and must be replaced. If battery voltage is still present at terminal No. 87 after disconnecting terminal No. 85, replace cold start relay.
3. If cold start injectors pass fuel when no voltage is present at terminal 87, the injectors must be replaced.