Thank you to anyone who can help me. I live in a real small town. There is this family that has been stuck here for 3 days living in their car. They dont have any money to pay a mechanic. I guess the guy changed his head gasket and now it wont start. He need to know the position of the timing chain and timing gear in relation to each other. He also wants the know that degree for setting the timing. All i know is its a 1990-91 nissan sentra 4 cyl and he said a 2.6 liter. Can someone please help me to help him.