1996 Chevy Blazer LS 4 door 4.3L vortec engine we were driving down the road and it was working good. Then I hear something pop in the front end. Right after that it got real rough skipping till we stoped at a light and it shut off. It will turnover but will not crank. We have changed the fuel pump sensor. Also the ignition control module has been changed

SUV was driving it and I heard a  pop sound in the front some where.  it started to skip really bad and shut off and has not cranked since, We have changed the fuel pump module or whatever it is called hooks into the fuel pump. We have also changed the ignition control module. It has not been very long since the plugs and wires were changed it had a fairly new distributor cap and rotor button. But it still will not run. It sounds like it tries to crank but does not.