Your main code looks fine:
Code:
START:
LOW GPIO.1 
PAUSEUS 4168 ' ON TIME
HIGH GPIO.1
PAUSEUS 4167 'DEAD TIME 
LOW GPIO.0 'SETS PIN 7 LOW
PAUSEus 4168 'FOR 4.168 MILLISECONDS 
HIGH GPIO.0
PAUSEUS 4167 'DEAD TIME
Your startup code does not:
Code:
TRISIO = %111111
This sets all pins to <U>inputs</U>. You want to use:
Code:
TRISIO = %001000 '(since GPIO3 is input only anyway)