fuel pump relay

[kman_e30]

i have an early 84 318i, i have a defective fuel pump relay(7 prong) does this relay run the fuel injectors or something else? mine clicks, but its not sending power to the fuel pumps, im trying find out what else its not sending power to. also wicth is the main fuel pump? the in tank pump or the external pump? are the in tank pumps usually pretty quite?

thanks guys

[Jaxx_]

iirc the wiring is for both fuel pumps but if they relay is clicking it should be sending out power. the relay needs grounding from a few different sources, including the DME.

The in-tank pump should be audible inside the cabin, however faint it might be. with no sound deadening in mine it is quite noticeable. It is the main fuel pump.

[Jaxx_]

1 - black - ignition coil power -- additional parameter for relay to switch.
15 - green - power distribution - hot run/start -- switch for relay
31 - brown - ground
30 - red - 12V+ battery
87 - red/white - "fuel control" not really sure.
87b - violet/red - Fuse 11 - fuel pumps


hope this helps

edit: seems red/white goes to AFM/hot side fuel injectors/throttle switch/barometer/"injection control module."

If you have 12V at the injectors but they aren't opening/closing you need to look at your "injection control module" which is the DME/ECU.

[Hey_You]

Try bypassing the relay. Make sure you don't send too much voltage to the pumps (not sure if they run off 12v or not). If the pumps kick on by bypassing the relay, replace the relay. I posted a wiring diagram a couple topics down. It's the layout for everything under the hood of an m10. It's pretty difficult to read, but you should be able to zoom in enough to make out where the lines go and what they are going to/from

[kman_e30]

i picked up a new relay from the junk yard today and it seemed to fix the problem, i think im going to buy a few spares just in case though, thanks alot for your help guys!