[rismo]

HI Guys,

Planning to hit the race track tommorow for 3 times 20 minutes.

All is fine, but only one high impact issue. When I turn off traction control, with a one press of DTC. So not fully off and i perform a corner when at that moment my rear wheels lose traction or let's say load is max and traction control ligths blinks I get a missfire with a limp.

Offcourse tommorow on the track I will not have any traction control enabled but I would like to know if this is standard / expected behaviour? Or maybe my fuel pump / plugs etc...

Is there an explanation for this? This to make my decision about tommorow track day. (It's racing not quarter mile, so a limp will cause yellow flags etc)

I do have a missfire error in cyl 5. Some weeks ago same happend on cyl 1 and 4.

Plugs are quite new, same for the ignition coils.

Thanks!

[rismo]

A second look on the codes gave me a cylinder injection shutoff of cyl 5.

[dzenno]

that's a very interesting misfire scenario...i know for example on e39 M5s if they're on the dyno and traction/ABS fuse isn't pulled out they won't be able to rev it out to redline and fuel will cut out...so yours could also somehow be related, not sure...

on this platform a detected misfire will trigger fuel injection shut off so that part of it is normal, question is where's the misfire coming from as it seems to be random across different cylinders...

i'd start with the easy: swap coils from cylinder to cylinder, then plugs, then injector(s)

[rismo]

My tech had some time during his lunch.
We reproduced the issue:

My gas tank was almost empty. As we have only one LPFP, this combination could result in a lowpressure / air pushed through the gas lines. The result of this was a cylinder injection shutoff.

Quote: It does not realy harm to have an almost empty gastank, although it's not the best for the pumps, the n54 does not like it as it can result in the above situation during cornering.

Another, but already known issue could have been the the silicone lines from the turbo wastegates, after a while they become worn and hard.. upon braking and then WOT this could result in a delayed transistion of the wastegates. Resulting in a limp.

Luckely my case was the first one!

@Dzenno,

Thanks for your advice.