Check out this routine.

I´ve been working out almost for a year and half now with a routine divided in 2 days. So now I´m trying to make a new one divided in four. What do you think about this one? Any ideas about changing or adding exercises, order, number of reps, etc greatly appreciated. I´m trying to bulk up.

Workout 1 - Back

Deadlift x 4 sets
Bent over rows x 4 sets
Chin ups x 4 sets
Barbell shrugs x 4 sets
Biceps x 8 sets various exercises
Too much back if I add Underhand Chin-up? And what´s the difference between Chin-ups and Pull-ups?

Workout 2 - Chest

Flat bench x 4 sets
Incline barbell bench x 4 sets
Cable flys x 4 sets
Triceps x 8 sets various exercises

Workout 3 - Legs

Squat x 4 sets
Stiff leg deads x 4 sets
Leg press x 4 sets
Leg curls x 4
Barbell Step-up x 4

Workout 4 - Shoulders

Military press x 4 sets
Upright rows/Power cleans x 4 sets
Lateral raises x 4 sets
Weighted Incline Twisting Situp x 4 sets
Hanging Hip Raise x 4 sets
Weighted Incline Sit-up x 4 sets (Do I target the entire abs with the 2 above? Is this one necessary?)
Forearms x 8 sets various exercises

1.5 years on the same program, WTF? Not to flame, but do you even read this site? There are plenty of routines on it, that would work very well for you (check out the FAQ section).