I recently put an '05 Durango 5.7 from a wrecking yard in my '03 ram 1500 4x4. I used the '05 fuel rail and injectors and all other sensors off of the '03. The truck would start great most of the time and wouldn't quite start others. It would crank and catch, but not enough to start. This morning as I tried to start it it had it's fit but I couldn't get it started before wearing the battery low. What could be causing the problem? My assumption is the injectors are bad and/or the throttle body/sensor. I have injectors on order and I pulled a other throttle body from the wrecking yard today. Any help would be appreciated.