E36 - Idle problem during deceleration

[Walt Bax]

On my 94 325is I have an annoying idle problem that causes the engine
rpm to fluctuate by +/-300rpm from the final idle speed when braking
to a stop. This occurs when I disengage the clutch when the car is
moving around 5mph and just about to stop. When the car is at rest,
the idle is constant around 600rpm. So far I have checked fuel flow
and pressure (in spec). Idle control valve keeps idle speed constant
with change in load (e.g. A/C compressor) so it's doing something.
O2 sensor was slow to react to changing air/fuel mixture (this might
be the problem). Any ideas?

Walt
94 325is

[Chris Scott]

Have had this probem before, seems to have gone away for me. I can't
remember what it is exactly off the top of my head, but i'll look for what
causes it, i have it somewhere saved.
Chris

[Randy Poznan]

Walt,

I just fixed a similar problem with my 91 318i M42 engine.
Look at your ignition system first. Clean all the spark coils, cap, wires
and remove and inspect plugs. I highly reccomend getting new wires and
new platnium high perf plugs. If cost prohibits wire replacement, use
ArmourAll to restore your old set. Don't forget to check the resistance
of the wires as well. If you have the original wire set or an OE
replacement the boot that connects to the plug usually has the spec.
resistance labeled on it.

My problem got so bad that when I ran the Air at a stop light the idle
speed would fluctuate to the point where I thought the car would die. At
low rpm's in 1st and 2nd gears the cylinders would misfire.

Remove 'BOGUS' from my email address if replying.

-RP

[Chaser]

On Mon, 03 Sep 2001 08:47:46 GMT, Randy Poznan
<rpozna...@nsimail.com> wrote:

>Walt,
>
>I just fixed a similar problem with my 91 318i M42 engine.
>Look at your ignition system first. Clean all the spark coils, cap, wires
>and remove and inspect plugs. I highly reccomend getting new wires and
>new platnium high perf plugs.

wo wo, slow down there buddy.. ehehe the M52 engine does NOT utilize
cap & wires. must be something else?

[Walt Bax]

Randy,

I have an M50TU engine that uses 6 ignition coils mounted
directly on the plugs. There are no conventional wires.
The coils were tested and *seem* ok unless it is an intermittent
fault when they heat up.

Walt

Randy Poznan (rpozna...@nsimail.com) wrote:
: Walt,

[peter]

Walt,
Does your ECU have a clutch pedal input? What happens to engine RPM if you
depress the clutch during other engine braking scenarios?

BTW, I fixed the rough idle problem I had on my 97 328i. I traded it for a
99 323i!

Peter
99 323i
"Walt Bax" <wb...@doe.carleton.ca> wrote in message
news:9n358g$qf9$1...@bertrand.ccs.carleton.ca...

[Vito Romano]

I think I have just solved this problem. I have a 92 320I and after
testing computers, coils , fuel lines etc, I still had the problem. The car
would miss and back fire and idile rough at low RPM. The Fix was to
re-charge the battery. I fly interstate weekly and only use my car 2 - 3
days per week. Battery is still fine but terminal voltage got to 12.1V
without engine on. Now it is around 12.4V and all is well.

Hope this works for you. I cost me a fortune at the dealer and they
couldn't work this out !!

Regards.... Vito

Walt Bax <wb...@doe.carleton.ca> wrote in message
news:9n358g$qf9$1...@bertrand.ccs.carleton.ca...

[Walt Bax]

Vito,

I'm not sure why that would make a difference. If the car is
running, the alternator would keep the terminal voltage around
14V so a bad battery should only produce starting difficulties.

Walt

Vito Romano (v...@bigpond.com) wrote:
: I think I have just solved this problem. I have a 92 320I and after

[Walt Bax]

Peter,

Interesting question! I'll have to check whether the clutch
position is detected and experiment with other scenarios.

Walt

peter (Peter...@junktodelete.home.com) wrote:
: Walt,

: >

[Walt Bax]

I checked the clutch pedal assembly and there are no switches
that are visible. There is no difference when I depress the clutch
during braking.