N20 Bad HPFP?

TaylorL · 01-13-2020, 03:20 PM

Hello everyone,

It seems highly unusual for the high pressure fuel pump to go bad on these N20's, yet somehow I think I've done it.
The car is a 2013 328i w/ xDrive, 86k miles on it. Driven pretty lightly, lots of freeway miles and 85% in Eco Pro. I did put on a BM3 stage 1 tune in September.

I had some oil dripping onto my downpipe and smoking up the cabin. General recommendation was to replace the valve cover, as they get old and tend to crack. Upon putting everything back in place, the car is not running well and throwing a low-pressure code: 11A002 - high-pressure fuel, plausibility: pressure too low (& 11AC02 - cold start version).
It bogs down before climbing when pushing the pedal quickly. It also won't idle below 1k rpm with the engine code. Clearing works for a few seconds until they come back up.

I monitored with the BM3 diagnostics and saw the LPFP is holding constant at 84 psi. HPFP ranged between 115-150 psi, target was between 1100-2800 psi.

I've taken the pump off and inspected it. Nothing seems broken. Is there a way to test these? Feeling very stumped at this point. Thanks in advance.

Link to BM3 datalog: http://www.bootmod3.net/log?id=5e1bc...OfcDUup8xaQjhM

JoeyF30 · 01-13-2020, 04:02 PM

This is why I personally will not tune my N26...

andino · 01-13-2020, 07:13 PM

Link to your log doesn't work. Perhaps repaste the share link again or make sure you didn't delete the one you're trying to share.

If your HPFP is only hitting 115-150 PSI when target is 1100-2800, I'd say you've got a bad HPFP which is the likely culprit to your issues.

TaylorL · 01-20-2020, 04:25 PM

Apologies for the long delay in getting back to you. I did end up having to replace the fuel pump. It seemed sturdy until I pulled on the plunger, at which point it came right off. Replaced it (and soldered the updated connector on) and we're all good to go now.

TaylorL · 12-20-2022, 10:06 AM

Revisiting and thought I'd add a little more detail to the problem. I think the plunger for the hpfp was broken when I tightened the bolts down the first time. If you don't alternate back and forth then it can get misaligned and snap the plunger shaft.
Also, be extra careful to not over-tighten! I ended up stripping one of the threads because of how soft the aluminum block is.

timmyc73 · 03-25-2024, 02:36 PM

Thank you for posting a follow up.

I just had the exact same thing happen to me. There are many DIY's out there, but only FCP was the one to mention that you must find, what is basically TDC, on the following cam for the pump in order to NOT break it upon installation. And you are correct on the removal. Go back and forth removing the bolts. Not sure when I broke mine, but it happened from not doing both of those orders of operation. I thought I did good research before tackling this?

01-13-2020, 03:20 PM	#1
TaylorL New Member 2 Rep 8 Posts Drives: 2013 328i xDrive Join Date: Apr 2018 Location: Salt Lake City, UT iTrader: (0)	N20 Bad HPFP? Hello everyone, It seems highly unusual for the high pressure fuel pump to go bad on these N20's, yet somehow I think I've done it. The car is a 2013 328i w/ xDrive, 86k miles on it. Driven pretty lightly, lots of freeway miles and 85% in Eco Pro. I did put on a BM3 stage 1 tune in September. I had some oil dripping onto my downpipe and smoking up the cabin. General recommendation was to replace the valve cover, as they get old and tend to crack. Upon putting everything back in place, the car is not running well and throwing a low-pressure code: 11A002 - high-pressure fuel, plausibility: pressure too low (& 11AC02 - cold start version). It bogs down before climbing when pushing the pedal quickly. It also won't idle below 1k rpm with the engine code. Clearing works for a few seconds until they come back up. I monitored with the BM3 diagnostics and saw the LPFP is holding constant at 84 psi. HPFP ranged between 115-150 psi, target was between 1100-2800 psi. I've taken the pump off and inspected it. Nothing seems broken. Is there a way to test these? Feeling very stumped at this point. Thanks in advance. Link to BM3 datalog: http://www.bootmod3.net/log?id=5e1bc...OfcDUup8xaQjhM
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01-13-2020, 04:02 PM	#2
JoeyF30 Private First Class 20 Rep 162 Posts Drives: BMW 2013 328i xDrive N26 Join Date: Dec 2019 Location: Iselin , NJ iTrader: (0)	This is why I personally will not tune my N26...
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01-13-2020, 07:13 PM	#3
andino Captain 480 Rep 681 Posts Drives: F31 328i xdrive Join Date: Jan 2019 Location: norcal iTrader: (2)	Link to your log doesn't work. Perhaps repaste the share link again or make sure you didn't delete the one you're trying to share. If your HPFP is only hitting 115-150 PSI when target is 1100-2800, I'd say you've got a bad HPFP which is the likely culprit to your issues. __________________ 2016 328ix F31 - SOLD! 2006 997.1 C4S
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01-20-2020, 04:25 PM	#4
TaylorL New Member 2 Rep 8 Posts Drives: 2013 328i xDrive Join Date: Apr 2018 Location: Salt Lake City, UT iTrader: (0)	Apologies for the long delay in getting back to you. I did end up having to replace the fuel pump. It seemed sturdy until I pulled on the plunger, at which point it came right off. Replaced it (and soldered the updated connector on) and we're all good to go now.
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12-20-2022, 10:06 AM	#5
TaylorL New Member 2 Rep 8 Posts Drives: 2013 328i xDrive Join Date: Apr 2018 Location: Salt Lake City, UT iTrader: (0)	Revisiting and thought I'd add a little more detail to the problem. I think the plunger for the hpfp was broken when I tightened the bolts down the first time. If you don't alternate back and forth then it can get misaligned and snap the plunger shaft. Also, be extra careful to not over-tighten! I ended up stripping one of the threads because of how soft the aluminum block is.
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03-25-2024, 02:36 PM	#6
timmyc73 Registered 0 Rep 1 Posts Drives: BMW f34 XDrive Join Date: Mar 2024 Location: Prescott, AZ iTrader: (0)	Thank you for posting a follow up. I just had the exact same thing happen to me. There are many DIY's out there, but only FCP was the one to mention that you must find, what is basically TDC, on the following cam for the pump in order to NOT break it upon installation. And you are correct on the removal. Go back and forth removing the bolts. Not sure when I broke mine, but it happened from not doing both of those orders of operation. I thought I did good research before tackling this?
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