its just cranking but wont start
my car just cut off when i was travelling and it never started again. on 2001 Chevrolet Blazer
Too many possibilities, have a machanic troubleshoot the cause. Anything else or suggestions is just guessing and does not help solve the problem, it just cost you more money by installing parts you do not need!! These vehicles have a lot of fuel delivery problems.
3 more answers
Put a gallon of gas in. If it starts, your fuel level sender has failed and you are actually out of gas. If not, refer to answer #1. May need to turn key a few times to prime the line.
check for spark and fuel pressure
The first place to look would be the ignition coil. If it fails while driving, the car will cut off. It will not create the spark to ignite the fuel and make the engine run until replaced. If there are no other obvious problems, it sounds like that's a good place to start.