Q: truck wont start , changed distributor cap and rotor

Hello. I would need to know what size engine that you have in your truck to be able to pinpoint what the issue may be. If it is getting spark then I would usually start by checking the fuel pressure. If the fuel pressure is not within specifications then this will occur. If it has good fuel pressure and spark then the ignition timing may be off. It may be an issue with the engine speed sensor or an electrical issue. It may be a failing module. I usually use my scan tool to identify if there are any sensors not working correctly. If the sensors are fine then the electrical system will need to be inspected. It can also be an issue with the valve timing if there is an internal engine problem. A compression test would identify this. If you want to have this starting issue checked, consider YourMechanic, as a certified mechanic can come to you to [diagnose why the truck will not longer start] https://www.yourmechanic.com/services/car-is-not-starting-inspection