99 Vitara, std, 125k km.  At times there is an idling problem.  The rpms will drop so low that she is just turning over . . . and then she shuts off.  It happend once before and the problem corrected itself, but it is back again.

there are no check engine lights and there is a new fuel filter.

Any ideas??

99% chance this ISN'T it...but...

My '96 had the typical (especially for that year) ECM capacitor leak problem.  If I started it up and just drove off, the first chance I had to let it idle (stop light, whatever), it would run like shit and die IF I didn't keep it revved above idle with the pedal.  It might be 200 miles later, but the first chance I'd give it to just idle on its own, pffff.  Your symptoms. 

Eventually, I stumbled into a workaround:  When first starting it, I had to let it run until it dropped down from "high" idle (not necessarily cold-weather-high-idle, just until it settled...) before driving off.  And this was a 5-speed.  After its idle stabilized, until I shut it off and re-started again it would run like a goddamn top, idle fine, 30mpg, day in day out.  Start it, wait a half a minute until the idle settled, then golden.  Most bizarre thing I've ever run into automotive-wise, but stone cold reliable.

Try that.  Otherwise, I got nuthin but loads of random guesses.

Tks BC.  I will give that a try.

you could also try cleaning the IAC. They could give you a prob sometimes also!

Um . . . .  IAC ? ? ?

Not sure what that is ? 

I A C stands for idle air control. They are usually boltrd to the side of the throttle body. They have usually a three wire plug. when you remove it should have what looks like a cone shaped plunger on the end. They can get dirty and cause some issues.