[ttsvetanov]

Hello guys. I am trying to deal with some problems on my recently bought E93 N54 2007

When the car is cold (not started for more than 5 to 6 hours) I am having a rough start with check engine light and of course limp mode. By rough start I mean normal crank start, but very bad engine work with loud injectors and RPM between 500 and 1500. After some seconds (maybe 30 I presume) the engine is starting to work normally (650~ RPM) with limp mode. Then if I shut off and start again the engine – everything is working smoothly. I repeat, this only happens on cold start.

Another problem (I think its not related to the first, but I am not sure) is cylinder injection cut when I kickdown. Restarting the engine is fixing the problem.

The error codes I am getting are:

0029DC – cylinder injection cut – the second problem
0029F2 – high-pressure fuel system, fuel pressure – after the rough cold start

I am not sure where could be the problem – the HPFP or some injector failing?

The things I’ve done so far by know:

- 002E8E – intelligent battery sensor, communication
- 002E98 – generator, communication
- 002E85 – electric coolant pump, communication
- 002E83 – electric coolant pump, energy operation
All of the above problems was fixed by changing the voltage regulator for generator.

- 0029F3 – fuel sensor, electric
- 0029F1 – fuel pressure plausibility
- 02AAF – Fuel pump, plausibility
All of the above problems was fixed by changing the low-pressure sensor with the new design of Bosh.

- 0029D0 – Misfiring, cylinder 4
The problem was fixed with changing the injector for cylinder 4 (with brand new index 12).
All of the spark plugs are also changed.

Intake valves are recently cleaned.

Thank you in advance and sorry for my bad english!

[ttsvetanov]

Added video with cold start:
BMW N54 Fuel preparation problems cold start - YouTube

[Rushan]

I would suggest on cold to remove spark plugs and see if any plug is wet or smell like fuel then it means leaking injector, if all plugs dry and clean then i would log the high pressure fuel pump and see how much it hold

[ttsvetanov]

The problem is solved, it was the HPFP. After the change of the pump, there is no any performance issues. Also the cold start is smooth. Thank you for the shared suggestions.

[g00b86]

Thanks for coming back and confirming this. I am having the same exact cold start problems but no CEL. HPFP was replaced under OEM warranty but now has over 100k on the replacement pump (I am over 200k miles) so perhaps I need to log this.

I was going to post a new thread and ask what people would log to start trouble shooting after checking plugs for leaking injectors etc. Thanks for following up and letting us know!