start then stall with puffs of white smoke from the intake.

[a799608]

98 s70 non turbo with 125k miles - car will start idol fine for about 30 seconds, start to spit and sputter, then stall. will then start and stall after 20 seconds, then work it's way down to 10 seconds. idol will dip, then pick back up, then start spitting again and stall. ocassionally i'll get a nice puff of white fumes from the air intake. i've tried unplugging the MAF with no change. any help??????