Cuts out on startup.

[Chris_D]

Noticed recently that if the zed has been sitting for a few days that on startup the revs would drop and the engine would cut out.
I can counter the cutting out by making sure to hold the throttle a smidge to keep the revs up and then it would settle down ok after a few seconds.
Not a devastating scenario but then not ideal either. Doesn’t happen again once the car is warmed up and i don’t experience any other anomalies when driving.
Cleaned the ICV a couple of years ago so I don’t think it’s that.
Did a scan and no codes alluding to anything relating to the engine.
Only thing I can think of is a clogged injector/s (?)
Been using BP95 over here in NL. May try a tank of 98 with a bottle of injector cleaner thrown in to see if that helps.
Any ideas?

 

[ph001]

It could be an air leak as the mixture needs to be quite rich at startup and if it's sucking air in through a split pipe it might struggle. Important to check the concertina elbow on the intake. VERY common failure on the M54...

 

[Chris_D]

Thanks but that's something I changed on the car when I first got it as it did indeed have a gaping hole in the elbow!

Current one is still in unholy health.

 

[Slackadder]

Thanks ph001

The girlfriend's Z4 "Zac" (our Z4 really) was exhibiting a rough start up just the other day. Checked exactly at that point on the elbow after searching the forums and hey presto split rubber (gaping hole). Quick trip to BMW parts and less than £30, lots of swearing and my back almost giving out (I'm old!) but he's all fixed.

Spent around 15 hours over the weekend on treating the roof, washing, clay bar (excellent) and waxing, so the back is really suffering!

Just took him (Zac) for a spin and he is sooo much happier (and makes me wonder why I have a 911 as well slightly). Thanks again for the excellent forum and help. Been a member on the TT Forum for years which has been equally a life saver.

Anthony