My car will not start

My daughters car will not start. I have checked the fuel pressure at the rail and it is at least fifty three pounds. I have checked the spark at all the wires. There is spark at all of them. I am thinking it is a timing chain but cannot figure out how to check the timing? I do not know where the timing marks are located. I checked two of the cylinder's for compression and there only about 80 to 90 lbs. There might not be enough compression for motor to start? My daughter said it was running fine and then when pulling into parking spot it kind of hesitated and then she shut off and went into store. When she came out it would not start. Can you please help me?