Amtrak expects to accommodate normal rail traffic between New York and Newark, New Jersey, during the Monday morning rush hour, spokesman Mike Tolbert said. Delays of as much as an hour on New Jersey Transit lines between the cities on Sunday were caused by a signal problem at a Portal Bridge switch and by planned weekend track maintenance, Tolbert said by phone. The switch has been repaired, he said. Sunday’s issues followed a meltdown on the Good Friday holiday on April 14, when as many as 1,200 New Jersey Transit passengers were stranded in a tunnel beneath the Hudson River aboard a train that lost power. New Jersey Transit and Amtrak, which owns the lines, have blamed each other for that incident. A week later, a power failure at a subway station in midtown Manhattan during the morning rush hour rippled through the Metropolitan Transit Authority’s subway system, halting trains underground.