Fuel pump or fuel pressure regulator?

Divo · Postby **Divo** » Fri Feb 24, 2012 10:25 pm

Using the returnless NB fuel system in a clubman. Engine starts and runs for about a minute or two and then stalls. Turn over again and starts straight away and runs again for about the same time. Has a brand new bosch fuel regulator. I have not touched the setting on the FPR, but it can be adjusted. Not sure if the pump is faulty or whether the regulator needs to be adjusted to increase fuel pressure? Any ideas ?

http://s637.photobucket.com/albums/uu94 ... C10030.jpg

thanks

Mark

spikes · Postby **spikes** » Sat Feb 25, 2012 1:00 am

Sounds like one of my bikes when I forget to turn the fuel tap on. Start it up, it runs till the carby bowls go dry, turn the fuel tap, fuel gets pumped in a runs again.

Sounds like there's not enough fuel to get to the injectors and they are squirting more fuel than its coming in and its running the fuel rail dry. When you start it up again, do you turn the ignition on but not crank it over and let the fuel pump pump fuel through or do you just go straight to starting it.

If the latter then it could be your fuel pump not providing enough pressure and the rails are still running dry. Probably be easiest to have a play with the regulator first and dial it up a bit before testing the fuel rail pressure

Russellb · Postby **Russellb** » Sat Feb 25, 2012 7:24 am

Divo wrote:Using the returnless NB fuel system in a clubman. Engine starts and runs for about a minute or two and then stalls. Turn over again and starts straight away and runs again for about the same time. Has a brand new bosch fuel regulator. I have not touched the setting on the FPR, but it can be adjusted. Not sure if the pump is faulty or whether the regulator needs to be adjusted to increase fuel pressure? Any ideas ?

Mark

How have you plumbed in the reg ??
should go pump-Tee piece-one line to fuel rail other to reg and reg other line return to tank
also is the fuel pump running when the engine stops?? or has it shut down

elpowell · Postby **elpowell** » Sun Mar 04, 2012 12:43 pm

Any checks of the fuel delivery system have to include a pressure test especially with a new adjustable regulator. This will answer quite a few of your questions. For example the system should hold full line pressure for at least 5 mins after shutting down. As for a returnless fuel system - never heard of this and to the extent that all fuel supply systems have to be able to keep rail pressure at full demand there has to be a way of bleeding off unused fuel back to the tank when less than full supply is required.

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