2000 GMC Sierra 5.3L will turnover but not start.

Question

will turnover but not start.

Answer 1

No start on any vehicles you need 3 things spark , air , fuel. Two of these are the most probable of the no start, The main would be fuel. Fuel pressure you need a adequate amount of fuel pressure and at least know if the fuel pump turns on. Cycle the ignition switch on you should at least be able to hear the fuel pump turn on, This would be a indication that the fuel pump works, but is it enough pressure. The specification for fuel pressure should measure 55 to 62 psi, with key on engine off. The next would be ignition this get a little more complicated as for its testing, you can use a scan tool and go to its live data, crank the engine the RPM  should register more than 250 RPM, if it does not more ivestigation is needed.