KiwiRail says Tranz Metro services on the Kapiti line have resumed after a fault stopped trains this morning.
An overhead power fault near Porirua left passengers stranded in a hot stuffy train for about 40 minutes.
Passengers on the 8am train from Waikanae took 2.5 hours to reach Wellington station this morning, a trip that usually takes a little over an hour.
This morning's incident is the fourth fault this year with the overhead power system on Wellington's Tranz Metro service.
One passenger estimates the train contained about 200 people.
Passengers evacuated through the end-door, and walked along the tracks to waiting buses.
This most recent incident follows a major disruption at Ava station last week when a train hit a power pole leaning over the track, damaging 150 metres of overhead cabling.