MG Sports Cars

I think that it is important to make the Advance Wiring kit and the Rover FI wiring work together. I know it is possible to connect a few wires and go but it seems right to use all the capability of the total system. My question concerns the fuel pump wiring. Advance, through a fuse powers up a relay that goes by a Yellow/Red wire to the fuel pump. At this point the FI ECU has no idea the pump is going and it is set up to have that information for some reason. What is wrong with connecting the Y/R wire from the Advance relay to pin number 86 F.I. Fuel Pump relay Number 21? Power comes from N wire to 30/51 pin on the FI relay. I am then using the W/R wire to trip the FI relay instead of the White/ Slate FI wire from the ignition. This is reported to the ECU by Blue/Purple wire to then be used by ECU as needed. I would then use the rest of Advance Y/R to go to the Fuel Pump from FI relay pin 87. First have I got the concept of the flow of power and information correct? Secondly does this make any sense to do or am I just making a simple circuit unnecessarily complex. My goal is to have a fused power point to the fuel pump and for the FI ECU to know about it.If the question is of any interest please comment. Do not hesitate to tell me that I am an idiot, my wife tells me that enough that I am used to it.

Hi Richard,

There are no idiots here, we are all just misunderstood.

As far as the fuel pump wiring. Let the ecu run the pump relay. The Blue/Purple wire is not a signal return it is a fuel pump request lead.
Wiring it as a signal return is going to damage your ecu.
The White/slate wire is the ign on feed to pin 19 on the ecu and term 86 on relay 21.
The Blue/Purple wire supplies ground to term 85 of relay 21 when the engine is running or cranking
You could use your Yellow/Red wire to power the White/slate or save it for something else.

Hope that helps.

Cheers
Fred

Ok makes sense to me. I was just trying to use the existing fuse set up in the Advance system but really not that hard to install an inline fuse and inertia switch like rover did.I can use my Yellow/Red wire from Advance to supply power to the pump. Thanks Fred I figured about one person if that would have any interest in my question.
Dick

You can still use your Advance fuse for the pump. Just connect it to the Brown 30 terminal of the 21 relay. Make sure to remove the brown wire from the circuit or you won't be able to turn the car off!
Cheers
Fred