Re: Re: 86 535i (E28) Running Rough

[Terry Peterson <tpeterson99@xxxxxxx>]

Alex,

Thank you very much for the information.  I will try it
this weekend and report back.

This makes sense since it did smooth out after the first
incident I described.

The reason I disconnected the battery was because the Bentley manual recommended it when removing the instrument
cluster.

Terry

> 
> From: alex.fadeev@domain.elided
> Date: 2002/09/20 Fri PM 04:05:19 EDT
> To: tpeterson@domain.elided
> CC: bmw-digest@domain.elided,  owner-bmw@domain.elided
> Subject: Re: 86 535i (E28) Running Rough
> 
> 
> Terry Peterson <tpeterson99@domain.elided> wrote:
> > I have an '86 535i that started running rough after the
> > battery was disconnected and then reconnected again.
> > This has happened to me twice in the past 2 months.
> >
> > The first time I removed the battery to try it in a friends
> > E28 that had a dead battery.
> > After I put it back in my car, It ran very roughly when I
> > started it and I had to keep my foot on the gas to keep it
> > running.  After a few minutes of this it smoothed out and
> > ran fine.
> >
> > Last week I disconnected the battery so I could remove the
> > instrument cluster to replace the service indicator batteries.
> 
> Terry,
> You did not need to unplug the battery for that.
> 
> > When I reconnected the battery and started the car it ran
> > very rough and I had to keep my foot on the gas to keep it
> > running.  It runs rough at idle and at higher rpms and it
> > still runs bad after it warms up.
> >
> > I checked for vacuum leaks, I checked all of the electrical
> > grounding and I checked the idle control valve and found no
> > problems.  Does anyone have an idea what this could be?
> 
> What you experience is normal.
> When you unplug the battery your DME looses all of its adoptive settings
> and need to re-adopt to your car.
> There are a few separate maps in the DME for idling, driving with partial
> throttle, with AC on, WOT. Probably many more. It will need to re-adopt all
> of those maps.
> This process takes anywhere from 30 seconds on newer cars to 10-30 minutes
> on older ones.
> 
> Give it time and the smooth idle should return. If it doesn't, then you've
> got real issues.
> 
> alex f

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