Though most present passive participles come from imperfective verbs, not all imperfective verbs can be used to form present passive participles. There is no rule, unfortunately, but the trend is that short, one-syllable verbs with concrete rather than abstract meaning cannot form present passive participles.
Here are some examples of imperfective transitive verbs in Russian that do not have present passive participle equivalents:
ждать[zhdat](to wait)
брать[brat](to take)
мыть[myt](to wash)
писать[piSAT](to write)
строить[STROit](to build)
есть[yest](to eat)
пить[peet](to drink)