RE: bad idle/Check Engine light???

["Fadeev, Alex" <alex.fadeev@xxxxxxxxxxx>]

The BOV! what? [mailto:flammingtwat@domain.elided] wrote:
> 
> My 87' 325is has had a few problems lately. The idle wont 
> hold(up and down)from about 500rpms to 1500rpms. Ruff start
> and hesitation or stumbling before car is fully warm. My 
> check engine light is on and is showing the O2 sensor at
> falt. I have replaced that with no luck. My next place to 
> look was goign to be the Mass Air Flow Sensor.

Why?
Did you reset the DME memory after installing the new 02 sensor? Did the
error go away?
Any other diagnosing hints? Does the car run rich/lean? Are you having rough
_cold_ or _warm_ starts?

> I have a cone filter,Jim C. chip, and exhasut could any of
> these modifications lead to a problem like this??? 

shouldn't.

> Any help would be appreciated thank you,

Jason,
Start with the obvious: your idle is unstable so look at the Idle Control
Valve (ICV). 
Bentley details the tests you can run on an ICV to check if it's still
alive. Those tests are not conclusive - some bad ICVs still test OK, but if
yours fails the tests you should start shopping for a replacement. Roundel
advertising junk yards will have one for around $50.

alex f

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