Who has fought & solved unstable idle issues? (M54 3.0)

[Bdc101]

I read somewhere that it is 3.5 bar +/1 0.2 bar.

Which would be 51 psi +/- 3 psi in good, decent, hard-working American units.

[Happy]

On mine coils, plugs, O2, MAF, DISA, ICV, and new vacuum lines. Make sure that the cap on the back of the manifold is not missing. This simple cap can cause a vac leak creating all types of symptoms.

Also, low grade fuel can cause issues especially if the above repairs are needed.

This solved idle, and stumbling issues.

E53 RiPPeR
XOuTPoST jUNkiE
ReVELaTiON 22:21

[Bdc101]

Coils, plugs, O2 sensors, MAF, DISA, ICV, and new vacuum lines... That's all it took? Why didn't I think of that.

Did you replace the longblock too, while you were in there Happy???

[Happy]

Originally Posted by Bdc101

Did you replace the longblock too, while you were in there Happy???

I kept throwing parts at it with no avail. And it wasn’t until all of the fore mentioned parts were replaced that the dang thing started to behave.

The vanos upgrade really made a difference also. But even without the upgrade, the idle issues, stalling and stumbling ceased.


E53 RiPPeR
XOuTPoST jUNkiE
ReVELaTiON 22:21

[Bdc101]

Thanks Happy.

[Happy]

Originally Posted by Bdc101

Thanks Happy.

No prob! It felt like It was a never ending parts free for all! LoL..


E53 RiPPeR
XOuTPoST jUNkiE
ReVELaTiON 22:21

[Bdc101]

Super weird, I drove 500 miles today and the idle was rock solid. I also didn't get any fuel trim check engine lights, or even shadow codes. (I only checked with the foxwell halfway through the trip though, so I will have to check again soon.)



I was unable to find a smoke tester or a fuel pressure gauge, so all I had done was take apart the intake hoses and reassemble, and clean out the idle control valve with brakleen. The ICV had no buildup that i could see other than being dirty.



Here's hoping that I solved both problems just by taking it apart and putting it back together again!


Edit: Note that I have taken this exact road trip two other times in the past 6 months, and it tripped the check engine light repeatedly on both trips with fuel trim exceeded codes. (I never see those codes at home but that may be because I usually never drive for more than 15 minute trips at a time.)

[Happy]

Originally Posted by Bdc101

so all I had done was take apart the intake hoses and reassemble, and clean out the idle control valve with brakleen. The ICV had no buildup that i could see other than being dirty.

I did this once when my X was all stock except for CAI and exhaust, back at like sixty some thousand. I switched to shell premium as well.

It cured it up until I put the blower on. After a year and a half or so after installation, it started acting up again. You know the rest of the story, part after part until complete restoration.

I don’t know if this applies to you or not but, my X was always particular about gasoline quality, blown or not. I always knew right away when I had pumped a bad batch of gas. I’ve never had any problems with Shell, and I always searched for a good clean station. I had my fingers crossed when I switched from gasoline to ethanol.

I’ve been through my fair share of M54 stalling, idling, and stumbling issues blown, and not. I’ve also gone through a few ICV’s also. I believe you are taking the right approach, make sure everything is clean, no cracks, and no leaks. A smoke test would still be a good idea.


E53 RiPPeR
XOuTPoST jUNkiE
ReVELaTiON 22:21