Log a cold start and that should give it away exactly where the problem starts from
Had the same issue with my hpfp
Sometimes it would log perfect psi sometimes it would shit it self
Can anyone help clarify using my log if my hpfp is bad or the output is acceptable?
I attached the lowest recorded psi at idle and highest recorded psi during the log @8lbs of boost
Usually this happens on occasion but it’s pretty mild and i can fix it by clearing the codes through mhd
However these past few times the misfire has not resolved itself and start getting.
In general you want to log your short term fuel trims (stfts) on both banks as well as long term fuel trims (ltfts) on both banks and ensure that they're not being maxed in either direction.
Replaced hpfp (genuine), lpfp (precision raceworks waldo 450lph), pressure sensor
Car still immediately throws malfunction and i don’t know what else to replace.
I have included a mhd data log starting prior to cold start
I do sometimes feel hesitation when accelerating but want a second opinion before dropping 1k just on the part.
What are the possible symptoms of hpfp (high pressure fuel pump) failure
Btw i cross posted this on n54 and n55 discussions because the e9x n54 and n55 uses the same hpfp so i'm sure they encounter similar issues.
37k subscribers in the e90 community
Lcd 535i, sudden failure of the hpfp
Per bmw covered under ext warranty
Hpfp installed at dealer car checks out in shop but fails on the test drive
After doing some reading about the n54 engine, i came across an article that stated that the hpfp is one of the major flaws of this engine.and bmw warranties it up to 100k miles or 10 years
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