iOS spritekit nodes stutter when transitioning from scene

I'm developing a game in iOS Spritekit using Objective C. I created a menu view in viewController and from that I'm calling a gameScene. In gameScene I uses five different nodes which has to released one by one randomly from the top of the screen. Each of those five nodes have 4 different images so it is stored in atlas. If the node moves to the bottom of the screen I change the image in the node and release from the top of the screen.

I'm releasing the node using the following code

Code:

self.wait = [SKAction waitForDuration: 1.0];
self.run = [SKAction runBlock:^{
if ([nodesArray count] > 0) {
   //select the node to release randomly and remove it from array
}
}];
self.seq = [SKAction sequence: @[self.wait, self.run]];

Those five nodes are stored in an array called nodesArray.

Now my problem is that I noticed a stutter when the nodes are released from the array. I don't know why these stutter are occurs as it's random, these predominantly occurs when the scene is restarted or If I come from another scene to game scene. When I come directly to GameScene without any intermediate scene with just a Launchscreen.xib , there is no stutter.

For restarting the scene I call the scene by the following code

Code:

GameScene *firstScene = [GameScene sceneWithSize:self.size];
[self.view presentScene:firstScene transition:[SKTransition fadeWithDuration:1.0]]

PS. I also tried implementing Menu as a scene and returning to game scene, nevertheless it too causes random stutter in the game scene irrespective of whether I remove the Node's & Actions before I leave the Game Scene.

This is the bug which is stopping me from releasing the game, so any help will be appreciated.