2007 r56 n12. have an issue with no pressure at 1st start of the day, and rough idle, like a chugging sound when trying to move forward or reverse. i have to usually leave it on the ON position to prime, and wait for the rpms to settle down a bit before moving.

using a pressure gauge w/car running, pressure would be at 54psi, but when off it would drop quickly past 45psi. i replaced the fuel pump and filter. tested the pressure, this time it stayed around 48psi after 20 minutes w/car being off. from the manual and your article, it shouldn't go past .5 bars.

but i still get the rough idle. i couldnt find any apparent leaks around the fuel rail/line or under the car. does the fuel rail have a check valve or is it only the pump? could it be the fuel pressure regulator on the filter unit?

also need to mention that i replaced the fuel injectors a couple months ago but can't recall if i had the rough idle before that. i bought the car a month before i replaced the injectors.
thanks in advance

__________________
This post was auto-generated based upon a question asked on our tech article page here: MINI Cooper R56 Fuel Pump Testing (2007-2011) | Pelican Parts DIY Maintenance Article

Cycle key so it reads 54, then restrict like at soft rubber section using hose clamping pliers, keep at 54, does engine start right up then stall?

- Nick