A nailer includes a power source including a piston reciprocating within a cylinder; a driver blade secured to the piston for common movement relative to a nosepiece; a magazine connected to the nosepiece for feeding fasteners sequentially for being driven into a workpiece by the driver blade; a fastener delay mechanism operatively associated with the magazine and configured for engaging a subsequent fastener and delaying advancement of the second fastener to the nosepiece until the driver blade returns to the pre-firing position after driving a leading fastener; and wherein the delay mechanism includes an electromagnetic solenoid with a reciprocating plunger connected to a pivoting cam member such that extension of the plunger causes the pivoting cam member to pivot into a blocking position between the fasteners.