timing chain issue on 98 blazer
 

hi i have a very puzzling problem with my 98 blazer. i was driving it to work last week when all of a sudden the motor shut off completely. i got it restarted for about 10 seconds but the engine was making a loud rattling noise as if the entire engine was shaking around. it than shut off again and i cannot get it restarted. i got my cousin to look at it as i am not very knowledgeable with vehicles and he is confused on why it wont start either.. there is fuel going to the engine and there is spark as well. i bought it 2 months ago and have never had a problem and no noises either.. it simply just died. it sounds like it wants to start but cannot fully turn over.. we heard it might have something to do with the timing chain but would like some input if anybody has an idea.