the fuel pump relay is plugged in to bcm in car, screen shot below of all fuses

 

Hi Mike, thanks for your fast reply and very helpfull information, as always in your threads. I've checked the fuse, relay and checked 12v is present to the pump when cranking. There's no fuel coming from the pump so ordered a new one now hoping nothing is damaged further down the line. I'll let you know.

 

i would use a direct live probe to fuel tank pump see if pumps fuel , also with diagnostics tool you can switch the pump circuit on which would tell you the circuit from bcm is working, sometimes the cas unit loses its rolling codes and then car wont start it switches off the fuel so wont start, if thats the case then main dealers ,

 

Hi Mike, thanks, I checked on the connector plug wires on top of the tank, it goes from 0v to 12v when the engine cranks. Once reconnected I put 2 tubes on the output and return fuel connectors (I didn't know which was in or out) into a bowl, and nothing happens, so hopefully just the pump.

 

thats the pump then, easy fix, check where the wires go to connectors inside they can come loose when do with fuel on them can build up carbon deposit and break contact might just find clean up and ie would solder them on personally ,, also the plastic pipe flexi can leak at where joins the pump or the top of sender unit ie can also crack, also the filter in there can clog with crud,

 

Hi Mike, so received the pump this afternoon but same issue. I've been caught out like a beginner .. The voltage on the connector does go from 0 to about 11.8v when cranking the engine but as soon as any load is put on ( I put a 25w bulb) it's stuck on 0v. So I did a s you suggested earlier, unfortunately I had already ordered the pump, and put a 12v power directly to the pump, it works and the engine starts after 1 sec.
So now I'm trying to figure out whats going on. I was thinking maybe the relay contacts were not good so put a jumper across to close the circuit but no success. Just wondering if there is another fuse or connector between the relay you mentioned in your earlier post and the pump?

 

Just wondering, on the Cooper D there's the outlet from the pump and what I gather a return circuit going back into the tank. Do these pumps run continuously or is there a pressure switch to switch the pump off when a certain pressure is obtained?

 

pump cicuit and injectors have a back circuit to tank for fuel, high pressure fuel pump has a regulator valve on it ie thats the item like below,

Pardon our interruption...

 

but as you have sent voltage to in tank pump and it starts off the bat then would say its a electrical issue within or around bcm , or might it be a cas unit doing it shutting off fuel feed so wont start from within it, auto electric guy might be your only path

 

Hi Mike, just had the bcm unit out as there was some post saying the soldered on relay is know to fail either itself or soldering points break. But no luck on my Cooper D there's an added piggy back printed circuit on top of the main fuse / relay board with about 20 pins to un-solder. Wasn't going down that path as may do more harm than good. So it's off to the electrical guy. Just wondering if it's ok to drive 30 miles to the garage with the pump running from 12v supply? Do they usually run continuously when the car is running or do the switch on then off when at correct pressure?

 

like i said ecu and bcm is specialist , bba remen on the uk do a service repair on them they de-solder the sandwich layer and replace the cheap crap soldered repays with better made ones and include a life time warranty , prettymuch when engine running electric pumps runs all the time, when first unlock car and put key in should prime pump ready to go , believe it pics up the pressure signal from fuel rail , ie rail pressure looks for a 5mpa ish pressure from fuel system before cranking, thats how I understand the system , if cas unit is faulty will shut fuel down from tank pump , i've seen many cars before that ths os the case or where battery fails and goes flat and strips the rolling codes from ecu to cas unit and will immobilise the system ie shuts down fuel feed from tank as well as some other parts of preventing it from being started or stolen etc, i had a petrol one do that a while a go and ended up paying a remapping firm to cheat the immobiliser and cas codes etc, so that car now has a ec that will start any mini just by plugging it is ,, ie must me same year and engine etc , if you find that just adding a live to in tank fuel pump then you could just wire the pump direct to ignition circuit perhaps , or run a switch to switch it on when want to use the car and off when parked up

 

I had to put a temporary power supply to a fuel pump on a different car and was advised to wire it in through the safety switch that turns off pump incase of accident.

 

Hi There,
What was the end solution to this problem? was it a BCM fault? We have the exact same thing going on with a mini countryman D