2016 F15 N63 4.4 Low Fuel Pressure

[Grizzles]

I am getting rough idle and acceleration issues. Wondering what my next step will be.
I changed the plugs and coils and still have the issues.
I did an OBD scan which is attached. The check engine light does not come on during the malfunctioning. Thinking it is the high pressure fuel pump. before I purchase the parts and do the repairs i was hoping someone has had a similar experience with this issue.

[Sophisticated Redneck]

Could be your injectors or your HPFP's, also could be low pressure FPs. Could also be your MAF's. I would pick up a wireless ob2 adapter and run something like the torque app which will display your fuel rail pressure in real time as well as your air fuel ratio and help point you in the right direction. I believe ISTA will allow you to test the injectors individually too.

[RED_Y_]

Run some ISTA tests first before buying parts.

[Grizzles]

Originally Posted by Sophisticated Redneck

Could be your injectors or your HPFP's, also could be low pressure FPs. Could also be your MAF's. I would pick up a wireless ob2 adapter and run something like the torque app which will display your fuel rail pressure in real time as well as your air fuel ratio and help point you in the right direction. I believe ISTA will allow you to test the injectors individually too.

Thanks for the insight. Here are some readings I got from my app.
Not too sure what it means.
Let me know if there is anything you can see from this or if there is more info to gather. These readings were taken at idle. One at cold and then warmed up a little.

[Sophisticated Redneck]

Originally Posted by Grizzles

Thanks for the insight. Here are some readings I got from my app.
Not too sure what it means.
Let me know if there is anything you can see from this or if there is more info to gather. These readings were taken at idle. One at cold and then warmed up a little.

Hard to say because it was at Idle, if you could screen capture or write down what it is under acceleration, your should be hitting close to 200bar (approx 3000psi) when under heavy acceleration and high rpm (over 4000rpm).

[Grizzles]

Originally Posted by Sophisticated Redneck

Hard to say because it was at Idle, if you could screen capture or write down what it is under acceleration, your should be hitting close to 200bar (approx 3000psi) when under heavy acceleration and high rpm (over 4000rpm).

Here is what I got when the engine was at 4-5,000 rpm.

[Sophisticated Redneck]

Originally Posted by Grizzles

Here is what I got when the engine was at 4-5,000 rpm.

Was it underload (Accelerating hard?) I ask as if just revving it up while its parked doesn't require much fuel. But if this was done under load then I would be highly suspect of your HPFP's as it should be closer to 170-200bar. They are pretty pricey though(about a grand each from the dealer or around 350 each if you get the Bosch equivalent.

I would still recommend downloading ISTA+ and running some further tests on it since the parts are so pricey.

[Grizzles]

Originally Posted by Sophisticated Redneck

Was it underload (Accelerating hard?) I ask as if just revving it up while its parked doesn't require much fuel. But if this was done under load then I would be highly suspect of your HPFP's as it should be closer to 170-200bar. They are pretty pricey though(about a grand each from the dealer or around 350 each if you get the Bosch equivalent.

I would still recommend downloading ISTA+ and running some further tests on it since the parts are so pricey.

i bought the HPFPs and have not installed them yet. i got this letter from BMW and was wondering if this was the issue.
my mechanic said to bring to them based on the letter and the issues i am having.

Thanks

[AZTWW]

Just again letting people with n63tu know these were symptoms I was getting before the engine went out at 43k. I think I had a faulty HPFP that was making the bank that my #5 cylinder was in run lean. Eventually the #5 popped and scored the wall. I was less than a year out of warranty. The hpfp never threw a lean code. It was only until after the long block was replaced, they put the same old one back on and I got more acceleration and misfires. Limped it to the dealer again and at first it wasn't warrantied until I asked them why they would put a failing hpfp on a brand new engine only to have it happen again. They spoke with BMW NA and came back saying I would owe nothing. Now the engine runs great as I probably never experienced it's true potential the whole time I've owned it.

[Grizzles]

Do i need the HPFP installer for this engine?
i dont see anything for the V8.

[skoold2003]

Originally Posted by AZTWW

Just again letting people with n63tu know these were symptoms I was getting before the engine went out at 43k. I think I had a faulty HPFP that was making the bank that my #5 cylinder was in run lean. Eventually the #5 popped and scored the wall. I was less than a year out of warranty. The hpfp never threw a lean code. It was only until after the long block was replaced, they put the same old one back on and I got more acceleration and misfires. Limped it to the dealer again and at first it wasn't warrantied until I asked them why they would put a failing hpfp on a brand new engine only to have it happen again. They spoke with BMW NA and came back saying I would owe nothing. Now the engine runs great as I probably never experienced it's true potential the whole time I've owned it.

Actually I remember seeing some codes about my engine running lean in the past.. maybe that's what led to my engine failing as well.

[AZTWW]

Originally Posted by skoold2003

Actually I remember seeing some codes about my engine running lean in the past.. maybe that's what led to my engine failing as well.

Yep, that's what I have been saying unfortunately. Mine never gave me lean warnings prior, which is odd but can happen. It was only until they put the old culprit HPFP back on a brand new long block where it started doing it again, threw a CEL and checked the code. Glad I caught it early enough without too much damage. My guess is there is a run of poor HPFPs from the 2014's that are going to start giving out on people and cause them to lose an engine.

[Grizzles]

Do I need to hand crack the motor for this replacement?

[skoold2003]

Originally Posted by Grizzles

Do I need to hand crack the motor for this replacement?

If you could crack the motor with your hand I'd think you wouldn't need a car.. you'd just fly everywhere

[Grizzles]

I used the alternator to crank the engine and it lowered the cam to replace the pumps.

once installed i found out that it most likely is the injectors, which is covered by the extended warranty.
I will post once this is reviewed.
dropping off car tomorrow.

[BMWdmk]

Sorry to bring an old thread from the dead but was it injectors or hpfp replacement that solved your issues?

[Grizzles]

It was plugs and coils.