318ti.org forum - View Single Post - How the FUEL pump relay gets signal from DME??

goyal99 · 11-06-2011, 03:48 PM

My 96 ti recently developed a weird fuel pump related problem. - I've tested the fuel pump and it's working fine...it spins freely and the fuel filter has been changed with a new one.

The problem is that I can JUMP (energize) the fuel pump by connecting the 30 and 87 pins after removing the FP relay and the pump runs fine...When I plug in the FP relay, I get NO POWER at the fuel pump and no power at the fuse (#18).

I have switched the relay with the DME relay and other relays and I still get no power at the pump....The DME relay an FP relay are next to each other and have the same pins and numbers in my '96 ti.....the minute I remove the relay and JUMP the 30 and 87 terminals I get power at the relay and fuse!!! - I get constant +12V power at terminal 30 (red wire) and power at terminal 86 (red/white) when key is in ignition or start position. I know the green/violet wire (terminal 87) goes to fuel pump itself.

My question is: WHAT kind of signal terminal 85 get from the DME?? It might be from the crankshaft or from some other sensor but I don't know for sure....Can anyone know for sure so I can solve my fuel delivery issue??

Thanks in advance - Bill

11-06-2011, 03:48 PM	#1
goyal99 Junior Member Join Date: Jul 2008 Location: Upstate NY - Poughkeepsie Posts: 8 iTrader: (0) Photo Gallery	How the FUEL pump relay gets signal from DME?? My 96 ti recently developed a weird fuel pump related problem. - I've tested the fuel pump and it's working fine...it spins freely and the fuel filter has been changed with a new one. The problem is that I can JUMP (energize) the fuel pump by connecting the 30 and 87 pins after removing the FP relay and the pump runs fine...When I plug in the FP relay, I get NO POWER at the fuel pump and no power at the fuse (#18). I have switched the relay with the DME relay and other relays and I still get no power at the pump....The DME relay an FP relay are next to each other and have the same pins and numbers in my '96 ti.....the minute I remove the relay and JUMP the 30 and 87 terminals I get power at the relay and fuse!!! - I get constant +12V power at terminal 30 (red wire) and power at terminal 86 (red/white) when key is in ignition or start position. I know the green/violet wire (terminal 87) goes to fuel pump itself. My question is: WHAT kind of signal terminal 85 get from the DME?? It might be from the crankshaft or from some other sensor but I don't know for sure....Can anyone know for sure so I can solve my fuel delivery issue?? Thanks in advance - Bill Last edited by goyal99; 11-08-2011 at 02:16 PM.