2003 Dodge Ram 2500 5.9 diesel got to where it didn't want to start. It would crank but not fire. Now, I know this is not a good thing, but if I give it a small squirt of ether in the air intake, it'll fire right up and runs great! No smoke. No hesitation. But once you cut the truck off, it won't crank without a little 'squirt'.

It'll only start with a 'squirt' and runs fine.