Turn the crankshaft of the engine with a starter and check if the starting injector sprays fuel.
If the starter injector does not spray fuel, turn on the fuel pump directly as above and connect the starter injector with BMW 61 1 440 wire harness in order to detect a fault in the starter injector connector or power lead.
If the connector and the supply wire of the starting injector are in good condition, check the operation of the thermal time switch.
Checking the tightness of the starting injector
Disconnect the block from the starting injector and wipe the starting injector dry: no fuel should flow out of its atomizer for 1 min.
If fuel comes out of the atomizer, replace the starting injector.