96 S10 Blazer won't start

Hi everyone, I hate that my first post here is a question but need a little help diagnosing this problem. My girlfriend went to start her truck this morning and said she heard a "pop" or click" under the hood and it would not crank or turnover the first 2 times she tried. But from the 3rd time on it will crank just not start, after you let off the starter it will chug and roll over just a little but never fire. Anyone have any ideas where to start looking first?

Hi everyone, I hate that my first post here is a question but need a little help diagnosing this problem. My girlfriend went to start her truck this morning and said she heard a "pop" or click" under the hood and it would not crank or turnover the first 2 times she tried. But from the 3rd time on it will crank just not start, after you let off the starter it will chug and roll over just a little but never fire. Anyone have any ideas where to start looking first?
First thing you should check is your fuel pressure at the shrader valve. Should be between 60 - 65 psi. Next check to see if you have spark. When was the last time you did a complete tune-up. Plugs, Cap, & Rotor? Check and let us know what you find.