ADD

Thanks for all the replies.

I was not intending to imply that the ethanol was directly related to the HPFP issues, although, I'm sure it doesn't help.

I was commenting more on the stumbling engine response.

I'm sure a lot of people have immediately jumped to "HPFP problem" when they get any kind of hiccup in the engine, as I did when I had the HPFP replaced and the stumble was still there.

I'm just saying that after draining the tank, my stumbling issues were resolved, and apparently not the FP.

bigbadbull

Bosch were the original designers, and they have been using it since at least 2003 in Europe on the VAG gas 2.0lT I4....I have not looked at the new Twin Charged motors to see it was used, but the principle of it comes from the high pressure Diesels that Bosch has worked on for eons...

BMW "Reverse engineered it" and had either Semiens VDO ( they build the newer ones I think) or Valeo built them for BMW. This is just what I've been told when talking to Engineers and Mechanics when at the shops.It's a very sore subject. Also I've heard the joys of changing the plugs on the new TTv8 in the F10's/01/07....PitA to say the least, very much like the same procedure on the old 928's if you have worked on one.

E90post has the trials and tribulations from several owners in Munich and in Scandinavia and other parts of Europe. In Munich they have even taken the cars back to the HQ for tear downs on the pumps to figure out what is going on and how to fix it.

bigbadbull

Also that happened on #2 of 5 for me. In fact they put another LPFP and set of Fuel Pressure sensors and drained the tank, 4 months later same issue.

Allen

So what is the latest on the HPFP anyway...I know there have been several iterations/revisions to date. Have they created one that is working?

Gene

nope..not yet....

njlou

This entire subject is so intriguing from a technical view. I know that BMW is best to keep their mouths shut on the details, but I have never read exactly what goes wrong.
You would think that some speculation or some real data would emerge.
Does the pump not pump enough, or does the electric motor quit, or does pressure back up into the pump???
And what is the low presure pump situation?
I understand that the HPFP is fed by a LPFP??

AND why dont they fix it??

bigbadbull

I know some have created a "lean" sustained lean situation that causes the Injectors to fail prematurely. A full set can run like $3k if they are not covered.

There are a bunch of different issues all classified HPFP Failure so it is some what case dependent.

r9ndy

I wonder if they have these issues with the f10. Makes me think twice about getting a TT bmw.

Gene

different engine and design. The x35 models have the single turbo N55 engine...no HPFP problems reported as of yet...but have read a few threads on X6 and e90 posts forums (the _35 models have the N55 engine as well) of wastegate rattles....