Turn the engine crankshaft with the starter and check whether the starting injector is spraying fuel.
If the starting injector does not spray fuel, turn on the fuel pump directly as described above and connect the starting injector using the BMW 61 1 440 wiring harness in order to detect a fault in the connector or the starting injector supply wire.
If the connector and power wire of the starting injector are in good condition, check the functionality of the thermal time relay.
Checking the tightness of the starting nozzle
Disconnect the connector from the starting nozzle and wipe the starting nozzle dry: no fuel should flow out of its nozzle within 1 minute.
If fuel appears from the nozzle, replace the starting injector.