Bad fuel pump…. How old is yours?

I suspect ICV needs cleaning.
Classic issue with M52 M54 engine, ICV dirty causing stalling at idle.
This is an issue that will never be picked up by a computer error codes.

The M54B30 has been around a long time. Those symptoms point to a vacuum leak, bad MAF, faulty disa valve or clogged idle control valve. VANOS might need new seals as well.

None of those will give you a code.

:thumbup: :iagree:

Bad fuel pump is easy to verify with a pressure/flow test.
Bad MAF will usually default to a "safe-mode" air/fuel ratio setting that provides acceptable operation until it's replaced.
Bad ICV should only affect idle and off-idle engine rpm and not affect cruise speed performance.
Bad DISA valve is number one suspect in my opinion.

https://germanautosolutions.com/prod...sa-repair-kit/

Good rebuild kit for Disa. When you remove disa, you can clean and check ICV at the same time.
If you wiggle ICV around you should hear metallic rattle/clicking


https://youtu.be/lVPV-XnmJyk

While you're replacing Disa and ICV, you'll be able to inspect most hoses for air leaks.

To rule our MAF, disconnect the connector and drive around. See if problem goes away.

Don't know the history of the vehicle but probably wouldn't hurt to change the fuel filter

My recommendation is do the m50 intake mod. Put a chaos calibration tune on it. Do an m56 valve cover. It has built in ccv. Refresh your vanos with the besian kit.

You'll eliminate DISA and all the crap associated with that intake that causes issues. You can even get rid of SAP, evap and icv. But it's best to keep icv.

You can run the same stage 2 tune that e46 m54b30s use.

I pass emissions no problem with that setup and tune. Except if your in California. They check software now for non oem tunes.

To rule out of your maf is bad without spending two bills on a new one find some in junk yard off of e53, e39 and e46 that have m54b30 motors. I get them for 15 bucks at mine. Just make sure they are the seimans ones. Not cheap knock offs.

Just my 3 cents. If your on a budget though just rebuild your disa and clean the icv. Check for vacuum leaks. See if that helps. Then try swapping the maf.

And don't forget to reset the adaptations. Do that with inpa, pa soft or insta

I would do more troubleshooting before purchasing parts. Right now it is very possible you will buy parts you don't need. DISA valve should throw a code and cause the check engine https://www.youtube.com/watch?v=phCuU6r4T9s One clear symptom is a rattling noise which would be the flap in the valve. If DISA valve is the problem it should be replaced ASAP as it can fall into the engine. https://bmwtuning.co/failing-disa-valve/

Another video to help troubleshooting: https://www.youtube.com/watch?v=AUTQ4we7uI0

And another for MAF : https://www.youtube.com/watch?v=M1m-n5rxuQs

For fuel pump: https://www.youtube.com/watch?v=eD0ixuUbibE https://www.youtube.com/watch?v=5S4pnw-kM2c

Usually there will be codes. Not necessarily calling out the actual cause but directional such as lean condition code if fuel pump is not performing properly. Can you check for trouble codes?