On the Bosch Jetronic equipped 33s the fuel pump should prime for 1 to 1.5 seconds,
as soon as the ignition is turned on.
If the pump doesn't prime, that may caused by:
- blown fuse of the fuel pump (7.5A), or bad connection of the fuse
- the fuel pump relay and/or the injection main relay doesn't engage (these are near to the aif filter box)
- defective injection control unit
- wiring fault
- fuel pump failure
The fuel pump can be checked by hooking up to an external 12V power source, capable to 45-50W (3.5-4A),
e.g. a battery charger will do, or you can use another 12V battery as well.
For safety reasons disconnect the electrical connections from the pump, before connecting the external supply.
The polarity is important, the pump terminal connected to the pink wire is the positive feed, the other with the
black wire is the negative. (If the pump spins up, you can try to start the engine)