won't start

I have a 1999 GMC Dually Sierra and just 3 days ago it will not start. It just turns over and over again. I changed the rotor, core, reset the timing and still nothing. Any suggestions??? I also changed the entire fuel pump system.

Welcome to AF, do you have spark at the plugs?, will it start if you sparay carb cleaner into the intake, do you have fuel pressure at the rail? 8.1 Vortec, no mention of engine.

Welcome to AF, do you have spark at the plugs?, will it start if you sparay carb cleaner into the intake, do you have fuel pressure at the rail? 8.1 Vortec, no mention of engine.



my engine is a 7.4 vortech, i found out that it is the timing chain. Can I please get some help in how to change this? I need help on how to set the timiing gears in place. Whether to set them up or down. I have a 1999 GMC 3500 Sierra 7.4 vortech motor. I need help!!!!