HPFP Replacement, Problem Ensues (pics)

[ChillFill]

Hey there guys,
I made a post here about 4 months ago. Long story short, when merging onto I95 I accelerated in taste (as every '35 owner should) and got the yellow half full engine malfunction light. Carried on cautiously. Has not come back on, car drove like nothing ever happened.

Until now. 4 or so weeks ago I got the same light while accelerating. This time, I felt loss of power; the car would not give me the power. Scanner shows up 2AAF, "Fuel Pump plausibility. As the engine runs smooth, and everything is completely fine (even with mild acceleration). If i were a soccer mom I'd probably never notice a thing. This eliminated the fuel injectors. Seriously doubt the lo-pressure pump.. and since these are notorious for the HPFP, I went with it. Bought the pump on eBay from BMW Atlantic for a very good price, actually. Replaced it with my old one. A fairly easy job, take off air-filter, (and the plastic panel that blocks it, along with the windshield wipers) air inlets, engine cover, and the intake manifold.

Put it all back together, deleted the code. Car revved very nice on neutral inside the shop. Trip back home, same thing. Yellow half full light pops on, and the car denies me the kick I've so long yearned for. Other than that, car starts perfect, engine runs smooth, everything fine even with mild-average acceleration. Step on it, that happens. Can it really be the low pressure pump?

Pics of the HPFP replacement:

[Dackelone]

Nice writeup! A lot of guys also replace the fuel pressure sensor that is on that metal pipe near the HPFP. For some reason that sensor also goes bad. The sensors runs ~$100.

So before you got that code and reduced power... did you not get a long cranking on cold start? Do you also have the new engine SW that runs the LPFP when you unlock the car? That was BMW's "band-aid" repair to "help" some cars from needing a HPFP.

Dack

[ianc]

I thought BMW had extended the warranty on the HPFP to 150k. Are you over that?

ianc

[ignote]

Originally Posted by ChillFill

Hey there guys,
I made a post here about 4 months ago. Long story short, when merging onto I95 I accelerated in taste (as every '35 owner should) and got the yellow half full engine malfunction light. Carried on cautiously. Has not come back on, car drove like nothing ever happened.

Until now. 4 or so weeks ago I got the same light while accelerating. This time, I felt loss of power; the car would not give me the power. Scanner shows up 2AAF, "Fuel Pump plausibility. As the engine runs smooth, and everything is completely fine (even with mild acceleration). If i were a soccer mom I'd probably never notice a thing. This eliminated the fuel injectors. Seriously doubt the lo-pressure pump.. and since these are notorious for the HPFP, I went with it. Bought the pump on eBay from BMW Atlantic for a very good price, actually. Replaced it with my old one. A fairly easy job, take off air-filter, (and the plastic panel that blocks it, along with the windshield wipers) air inlets, engine cover, and the intake manifold.

Put it all back together, deleted the code. Car revved very nice on neutral inside the shop. Trip back home, same thing. Yellow half full light pops on, and the car denies me the kick I've so long yearned for. Other than that, car starts perfect, engine runs smooth, everything fine even with mild-average acceleration. Step on it, that happens. Can it really be the low pressure pump?

Pics of the HPFP replacement:

I've had both replaced if that matters.

[ChillFill]

Originally Posted by Dackelone

Nice writeup! A lot of guys also replace the fuel pressure sensor that is on that metal pipe near the HPFP. For some reason that sensor also goes bad. The sensors runs ~$100.

So before you got that code and reduced power... did you not get a long cranking on cold start? Do you also have the new engine SW that runs the LPFP when you unlock the car? That was BMW's "band-aid" repair to "help" some cars from needing a HPFP.

Dack

No long cranks even on a cold start. Car turns over perfectly and runs like nothing ever happened, until I try to accelerate.

Did not replace the sensor, our current scanner only shows up the fault code I mentioned, thinking of taking it to BMW at the end of the week for a diagnostic. Then again the diagnostic alone will cost me that of a new sensor or LPFP.

The new engine SW? I'm afraid Im not sure what that is, could you elaborate further?

[Dackelone]

ChillFill
ianc
ignote

Originally Posted by ChillFill

No long cranks even on a cold start. Car turns over perfectly and runs like nothing ever happened, until I try to accelerate.

Did not replace the sensor, our current scanner only shows up the fault code I mentioned, thinking of taking it to BMW at the end of the week for a diagnostic. Then again the diagnostic alone will cost me that of a new sensor or LPFP.

The new engine SW? I'm afraid Im not sure what that is, could you elaborate further?

The last pdf is the SIB on the SW update. Basically before BMW issued a service campaign extending the warranty on the HPFP on up to 2010 M.Y. (all N54 model)cars... BMW came out with a SW update that was kind of a "patch" to help failing pumps last a little bit longer. What BMW did was run the LPFP when you unlock the car(from its "sleep").... the LPFP would help prime the HPFP for a faster startup.

Basically you can tell IF your car has the SW update is when you unlock your car... you should be able to hear the LPFP run for a few seconds(10 secs or so), before you even sit inside the car to start it.

IF someone's HPFP is dying... ask a dealer about a free replacement(USA only). Over here in DE... my German dealer told me they often will replace the HDP(HPFP) IF a customer has been loyal and taking their car in for regular BMW services at the Zentrum. They also told me its rare that a HPFP fails. They said its more of a "USA thing". IDK. I know my 2010, N54 135i has its original HDFP going on 132K kms. fingers crossed.

Dackel

[ChillFill]

Hey guys, so we got a new ODB scanning computer in the shop a week or so ago, so i decided to give it a scan. Got a low pressure fuel pump plausibility code. Bought a new pump, seeing as it's fairly cheap and installation is easy, it should be a quick fix. One thing that scared me is; when I was looking up videos of the LPFP installation to see if it's location is under the seat, many search results came up with the LPFP SENSOR. I ordered the pump, thinking my sensors are good as the scan did not single out a sensor. I hope this is still the case, will be installing the new LPFP today.

[Silenus]

For the record, 2AAF is usually a fault to be ignored or a complimentary fault. I think you had other faults stored the entire time.

http://www.e90post.com/forums/attach...1&d=1260025842