I have to use starter fluid to start then it runs just finest it's a pain to do ,what can i check?

 

Sounds like you have excessive return flow from injectors or the high pressure fuel tubes are leaking. Also make sure your batteries are fully charged and the starter motor is able to crank engine over to at lease 150 rpm. If you have a way to monitor rail pressure then I would start there. If not then I would tighten down all the injector connector tubes to 41 ft. lbs. If that works then you fixed your truck, if not then you need to cap injectors one by one until you find the one causing your no start. You will need a capping tool available online. 9864A Fuel Rail Block Off Cap 9864

 

Thanks for the info,that cap is for a6.7 mine is a 5.9 i don't know if that would work. All though i will tighten everything up and see what happens. Thanks again

 

If the batteries are a few years old - buy two new ones and install them. Sometimes one battery will get weak and the electrical system will draw off of the stronger battery. Eventually the better battery will fail.