[AndyM340i]

Hi Guys,

I have a 2018 M140i running a BM3 Stage 2 OTS map with the correct supporting mods - MST induction, downpipes and uprated HPFP (TU). The car has been running this spec for 6-months and has done a ring trip - no issues. A week or so ago the car developed a fault where it would not start. Fault traced to faulty fuse box (in boot). Fusebox replaced and car starts fine.

Now I have a weird issue...

At high RPM (normally 4th/5th gear, about 5k RPM) the fuel rail pressure crashes and I lose power. After the loss of pressure (measured using a live graph on my Autel) the car runs okay and then I lose all power (usually after 1-2miles after pressure crash) - accelerator does nothing. I pull over and idle is perfect, but the car will not do more than 5mph and its very jerky as if it cannot get enough fuel. I cycle the ignition and then its fine...until I try and use full power again.

When the rail crashes the EML light does not come on. I scanned immediately following the issue and the codes are:

213901 - Power management: reduction or shutdown of individual electrical consumer.
8040B9 - De-activation of terminal 30B: Top startability reached.
8040BD - Reset of deactivation of terminal 30F.

I only saw these codes today as I have not had my diagnostics with me on previous occasions. I have chaged: EPKM, LPFP, Fusebox (due to previous starting issue). HPFP is purely mechanical, driven by the camshaft, so I do not believe that is at fault.

I'm stuck - any ideas?