I was driving and came to a stop sign and it shut off. It cranks with no problem,just wont turn over. My mechanic seems to think it might be either the fuel pump or a security issue...Any other ideas? Please help. I have a 2001 blazer 4door, 4.3L.

 

It seems with Blazer's it's usually the fuel pump. Check the relay and make sure it's good then get a fuel pressure gauge and check the fuel pressure on the shrader valve.

 

Turns out it is the fuel pump. Something simple to fix,but expensive. Thanks for your input.