Is it my HPFP?

[dsh135]

I'm hoping the collective wisdom/experience of the forum can help me out. I have a 2011 135i (N55) that is a Mar 2010 build with almost 70k miles. I've been running a JB since late 2010 and ISO for about 18 mos.

After no cranking/idle issues whatsoever, back in December I started getting slightly extended cranks (~2-3 secs) and a bit of RPM hunting on start-up. That's how it's been for the last 6 months until yesterday I got an unusually long crank (~5-6 secs) with very rough idle and a half engine light. 100 yards down the road it goes into limp mode.

The only code that is being thrown is one for boost cut, probably a result of going into limp. I have cleared it several times as well as done adaptation reset and still get the half engine light and limp code right after start-up. Idle is brutal and seems to be following the exact same pattern every time:

1) crank is 1-3 secs
2) car starts and idles ok for about 5 secs
3) rpms rise to about 1200 then drop to about 400
4) idle then oscilates at low rpms, sounding like it might stall and shaking the car


During this there is a strong fuel smell and unburnt gasoline droplets coming out of the exhaust. That may be from running in limp mode.

So far the only thing I know for sure is that it is not the coils (swapped them out with our X3 and they are fine) and not the JB4 (removed it and went back to stock). I pulled the spark plugs and they all look the same and are generally tan with a little bit of sooty deposit starting to build-up, probably because of running rich in limp mode since yesterday. There is no wetness to indicate a leaky injector. Finally, I also did the "screwdriver listening test" on each of the injectors and they all seem to be ticking away.

Is there anything else that could be a likely cause before suspecting the HPFP or is that the most likely conclusion at this point? I find it odd that there are no codes other than the limp code.

Thx

[ShocknAwe]

Pull the negative lead from your battery for a half hour and see if thatthat changes things.

[dsh135]

Thanks, just gave it a try. Unfortunately no change.

[ShocknAwe]

Jb4 on latest firmware?

[mike@x-ph.com]

It is odd that you are not getting other codes with the limp mode code.
It sounds like a HPFP issue, get it checked at your dealership it is still under warranty until 100k.

[PA135i]

HPFP is 10 years or 120K.

[dsh135]

It sounds like a HPFP issue, get it checked at your dealership it is still under warranty until 100k.

I'm not sure the extended warranty applies to my car. It's a MY 2011 with an early build date of Mar 8, 2010. I was under the impression that the extended warranty only applied to N54's (?)

[dsh135]

Restarted yet again and let her run a little longer this time, running the RPMs up to about 3K. Got a sh#tload of codes this time, all related to cylinder misfires. Would I be correct in assuming that with misfires on every cylinder that it is unlikely to be one or two injectors that are faulty?

[ShocknAwe]

Take it in.