Re: repl :1990 525i stalls after battery change

[john <j.s.smith@xxxxxxxxxxxx>]

On Thu, 5 Oct 2000, Eugene Hoe wrote:

> Is your idling very eratic after changing the battery?. When u
> disconnect the battery, the ECU 'forgets' it optimal settings like
> idling, etc. So what u need to do is start the car up and let it
> idle for at least 2 - 3 hours. The ECU will then learn back the
> optimal settings and idle smoothly again.

Holy moly, idle for 2-3 hours?!?  My E30 325 has the same brain I
think, and after battery disconnection, it only takes about 10 miles
of normal stop & go driving to adjust it back to normal.  I'm no
motronic expert, but it would seem that hours is too long, and that
something else might be amiss...

Have to agree with John... 2-3 hours has to be too long (I guess it
would test the thermostat is working :-)) I don't actually know for a
fact but would have thought idling for that length of time may well not
do the engine much good (the oil pressure may not be at optimum). From
my experience with my 89 325i, its not so much the time but the
variation that does the trick: start, idle, drive some, stop, engine off
cycle. The motronic soon seems to "learn" the new parameters. Just
bliping the accelerator from idle a few times seems to help too. 

Check the air-idle valve isn't sticking. (Listen to it with the ignition
on and engine off - it should make a quiet buzzing sound... and could be
sticking even if it buzzes!)


- -John


> From: Stowe Spivey <spiveyspivey@domain.elided>
> 
> I changed my battery and now it stalls out at every stop light for
> several days now.  Any ideas are MUCH appreciated.

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