[Raptor04]

Anyone know what fuel mode 22 and a surging rail pressure at idle means? Rail pressure oscillates between 680ish to over 2100psi at idle and changes from Fuel mode 2 to 22 when the rail pressure spikes and then changes back to 2 when rail pressure comes back down to normal. Is this an injector issue? My bank 1 afr is also slow to respond when lifting off throttle, i.e., bank 2 afr goes to 234 when lifting off throttle but bank 1 doesn't reach 234 or reaches it much slower than bank 2. Injectors are Index 12 and almost 2 years old. Spark plugs are brand new, coils are b58 coils and 2 years old. HPFP is probably the oldest part on the car and was replaced in 2015. Car is 2009 N54 335xi.

Any ideas on if this is normal or an issue? I continue to get some lean to rich afr oscillations when driving in low load/vacuum state and think fuel mode 22 might be the issue there as well...need to log.

[Saif2018]

Originally Posted by Raptor04

Anyone know what fuel mode 22 and a surging rail pressure at idle means? Rail pressure oscillates between 680ish to over 2100psi at idle and changes from Fuel mode 2 to 22 when the rail pressure spikes and then changes back to 2 when rail pressure comes back down to normal. Is this an injector issue? My bank 1 afr is also slow to respond when lifting off throttle, i.e., bank 2 afr goes to 234 when lifting off throttle but bank 1 doesn't reach 234 or reaches it much slower than bank 2. Injectors are Index 12 and almost 2 years old. Spark plugs are brand new, coils are b58 coils and 2 years old. HPFP is probably the oldest part on the car and was replaced in 2015. Car is 2009 N54 335xi.

Any ideas on if this is normal or an issue? I continue to get some lean to rich afr oscillations when driving in low load/vacuum state and think fuel mode 22 might be the issue there as well...need to log.

Fuel mode 22 should be injector adaptation from what I read, not sure what it represents exactly but have all the injectors been coded correctly?

AFR's not shooting upto straight away to 234 when you go off throttle could indicate leaking injectors. Pull the plugs and inspect all of them for fuel, smell of gasoline etc

Since your at it, may as well check all injectors visually and recode all of them. Make sure to replace seals.

[Raptor04]

I also get rough starts after driving car hard and then doing a warm restart. I'm leaning towards a leaking injector on bank 1.

[sam.335is]

i know this post is 2 years old but please tell me you have a solution my 335is doing the same shit on index 12s

[konstat]

Originally Posted by sam.335is

i know this post is 2 years old but please tell me you have a solution my 335is doing the same shit on index 12s

Is it switching back and forth between fuel modes? Fuel mode 2 is normal operation and fuel mode 22 is spool mode. In spool mode the DME references different fuel, timing tables, etc. Something is telling the DME to fluctuate between the modes. My guess is throttle related issue. Are you able to send a log so we can see what the other parameters are doing

[Raptor04]

I went back to stock spark plugs and that seems to have eliminated this issue.

[sam.335is]

i haven’t checked what mode it’s in i just saw that my fpr psi went to 2300 at idle and made injectors sound crazy, but only at idle so far, is this the same for u? also how do u check the mode

[sam.335is]

little bit new to the computer side of things , logs etc

[sam.335is]

also thanks for responding it seems no one else has high fuel rail pressure at idle issues and you are the one person whose gotten back to me