Won't stay running
2003 Dodge ram 1500 5.7 starts but dies
I just had the problem where my dodge 1500 2001 5.9l would start but wouldn't idle. It was because my battery didn't have enough charge. It would start and then die. Turns out that the starter works at like 8 volts but the engine needs about 12 to 14 volts to idle.
The starter motor needs about 12.5 volts to properly turn. Once the engine is running, it's no longer running on the battery, but on current produced by the alternator, and that's about 14.6 volts. It's likely that your start-then-die problem is due to a defective alternator.