idle issue?

[CLASH]

hi everyone, I recently just bought a '98 325i
I never own an Germany car before, the issue I having right now is:
its a winter time here in Canada every time I start the car the RPM is staying at around 700rpm
and if I just leave it like that for few minutes car car will die and battery drained so I will not able to start again.
but if I start it and rev up the engine to around 1500 for a few seconds the car will stay idle at 700rpm and not die.
so I owned 3 Honda everytime I start like cold start the engine will stay at around 1500rpm and goes down as engine gets warmer.
but this BMW that I got every time I start it only stay at 700rpm, so is that normal for this type of car?
and why does it drain battery if I don't rev it up?



thanks

[peytonracer4]

you need to look at your alternator or voltage regulator.
mine idles high at first for maybe 5 seconds and then settles. my e46 does something similar but never idles higher than 1100
i know what you mean about hondas. they will idle high until they sense the coolant getting warm.

the dying is probably alternator related but it's hard to say with such little diagnosis.

[CLASH]

I checked the V. It was 12.4v what it off, and ~13.9 when engine is running.
And one thing I really sorry for misspelling my is 1989 325i e30 :)
And do you think the fuel filter is,causing the problem?
Some time I take a look at the engine bay I saw the bottom of the fuel filter is wet.
Or my engine is running rich? Misfires?
At the idle some time I feel like the car shake for a bit.


Thanks