SOLVED Losing fuel pressure and my sanity :(

Dandy.93

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Nov 24, 2020
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Hey there lads. Never thought I would have to post on forums for help but here I am. I have a 2008 335i (N54).

So recently my car has been feeling horrible and having symptoms of HPFP failure :( :
1. Rough cold start
2. Feels like misfires when under mild acceleration.
3. If I accelerate for more than a couple of seconds the engine shakes and violently jerks the car, cutting the turbos out and shutting off the HPFP. Rail pressure drops and matches the low-pressure fuel pump (85 psi). This causes the car to blast the radiator fan to full power and go into limp mode. I can temporarily solve this by shutting the car off and on again.

Oh and another thing.
4. Odd high pitched siren/whistle sound when under acceleration and metal clank noise? But no wastegate rattle. Might be a separate issue?

Codes :
29f1 - Fuel pressure plausibility
29cf- Misfire (probably caused by the drop in fuel pressure)

Since I know it's pretty common for our HPFP's to fail, I ended up buying one off FCP euro for $780 and installed it.
BUT unfortunately no luck. The car still violently jerks and shuts off the HPFP and I don't know why. I'm losing my damn mind with the car and I've only had it for a year. šŸ˜”

I managed to make a quick log after installing the new pump showing the fuel pressure dropping and skyrocketing my afr:

And this is what INPA showed in error memory:
Desktop Screenshot 2020.11.22 - 14.53.11.86 (2).png



It appears that the P-Code assigned with the 29f1 code is P3284. Definition: Fuel pressure control Bank 1 calculation of adaptive fuel volume implausible.

I'm fairly new to the car scene so any help would be greatly appreciated!. šŸ™‚
 
Solution
The problem was found after 1 year and four months. In case anyone else has to go through this rabbit hole according to BMW of Arlington the issue was damage on the cylinder head. Caused by an incorrect injector bracket bolt. It was slightly longer than the correct one and it "punctured the crankcase". Surprisingly after 120k miles, my compression was 190-198 psi on all cylinders. Pretty good but oh well.

wheela

Lieutenant
Jun 4, 2021
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Twin Cities, MN
Ride
2015 e84 X1 35i Msport
So besides the rail pressure.

Looking t your posted log makes me raise my eyebrows.

As soon as your log starts you get this:
View attachment 46753

Your Lambda AFR Bank 1 is rich af although STFT1 is pulling max fuel (-34%).
There is something going on on your Bank 1 which may correlate with defective injectors. There may be one or more stuck open.

OR your tune is fu**ed up badly.
OP - do you have any new logs since they replaced injectors, fuel pumps, etc.? This fueling issue on bank 1 is a huge clue. I agree, this log looks like an injector stuck open, curious if logs still looked like this on bank 1 after new injectors?

Not sure how a cracked block explains this log. If your logs still look like this, I wonder if an injector output on your dme is stuck in the on position?
 

Dandy.93

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Nov 24, 2020
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OP - do you have any new logs since they replaced injectors, fuel pumps, etc.? This fueling issue on bank 1 is a huge clue. I agree, this log looks like an injector stuck open, curious if logs still looked like this on bank 1 after new injectors?

Not sure how a cracked block explains this log. If your logs still look like this, I wonder if an injector output on your dme is stuck in the on position?
Started it today just to get some logs. Sounded great idlingšŸ™‚. Not the best logs since the car jerks and pings under acceleration.

3rd gear log: https://datazap.me/u/angelz0418/latest-data-log?log=0&data=14-15-19-20-21-22
-Had to shift pretty early because of hesitation.
-At 2700 rpm the DME starts pulling STFT. At 3000 rpm it reaches -34 :confused: , AFR on bank 2 hits a low of 11.5

Mid shift log: https://datazap.me/u/angelz0418/latest-data-pt2?log=0&data=14-15-20-21-22
-The same thing happens at 2800 rpm -34 stft with low AFR

Here is the terrible sound it makes under acceleration (I stuck a phone in the engine bay):
Any thoughts on what that whistle is? Also that clanking sound?
Here is how the car sounds idle:

I can't replicate the sound by revving only when driving. Not sure how a cracked block would make that noise.