M54 2.2i Rev's are slow to come down

[Lee]

So as the title suggests, a few times I have taken Sam's 2.2 zed out and found the throttle response interesting. The car rev's up nicely but is very slow on the return to idle. So far I have removed all the hoses up to the inlet manifold, I've also removed the ICV and cleaned it out. This has made it better but not got rid of the problem. Seeing as these 2002 model zeds are fly by wire I'm guessing there is a way to reset them maybe?

Anyone else had a similar issue?

Lee

 

[GazHyde]

You can rest the throttle, will try and dig out the instructions when I get home unless someone's beats me to it.

I think you said you read the codes last night didn't you. Is the car down on power at all?

 

[Lee]

You can rest the throttle, will try and dig out the instructions when I get home unless someone's beats me to it.

I think you said you read the codes last night didn't you. Is the car down on power at all?

Yeah read the codes last night, All I got was an O2 sensor fault. Cleared it and it seems to have stayed off for now.

 

[Dickymint]

I have the same thing on my 2.2i changed all pipes and cleaned idle valve and done vanos, some times its ok and sometimes not I have watched and throttle works of i.e it goes back ok and not sticking (I know its fbw) so I'm at a loss.
also changed cam sensor and new MAF

 

[GazHyde]

I was wondering around the area of exhaust issues. Blocked cat perhaps although I'd think that would be more severe symptoms from what I just read - hence being curious about power being affected.

 

[Dickymint]

new middle cats and no baffles in my exhaust and no errors or rattles

 

[Wookee]

Sticky butterfly??

 

[Rudyrov]

My 1998 2.8 US Version has the same issue, it is difficult to shift quickly because the throttle hangs on the way down, it revs fast and has great power. I also have a muffler delete and have replaced it with a flow through muffler. The engine runs great, burns no oil and I maintain it myself with regular oil changes and a new 02 sensor put in about 8 thousand miles ago (trying to improve lead foot gas mileage)
I have little over 108,000 miles on it and bought it with 80,000 a few years ago. I love the car but hate this type of throttle response.

 

[EnthuZiaZT]

I think this is caused by a sticking or worn throttle unit. If this is replaced I think it will cure the problem.

Mike

 

[Rudyrov]

I'll have to check that out. Thanks Mike

 

[Rudyrov]

Here is a thread from another forum that goes into further detail, perhaps this will help.
http://www.bimmerforums.com/forum/showthread.php?1215816-Faster-rpm-drop-at-clutch-in

 

[Antm72]

I was wondering around the area of exhaust issues. Blocked cat perhaps although I'd think that would be more severe symptoms from what I just read - hence being curious about power being affected.

I found after the exhaust and filter change my zed drops the revs to idle like a stone, compared with before it was done where it was abit more leisurely. I suppose an 02 sensor that misreads may cause the car to fuel slightly different and revs drop slower coping with burning off any excess fuel?