Hello, I have a 2002 Ram 2500 with the 5.9 magnum, it will crank over but will not start. It wouldn't start up last night so i had to have it towed. I sprayed some starter fluid and it will run a little when I spray starter fluid in the intake, but as soon as i stop spraying the engine dies. Earlier that day it took more cranking over than usual to start it, and the idle dipped for about a second at a stoplight. I believe it could be a fuel pump but could it be a sensor or something else? Any help would be appreciated.

 

If it runs on starting fluid the fuel pump is the prime suspect. Could be the fuel pump relay as well but that is easy to check. There's also a test port on the fuel rail.

 

Just opened the test port and there is absolutely no fuel in it. I also do not hear the fuel pump kick on like i usually do. The relays are all fine, so it has to be the fuel pump

 

Verify that you get power back to the pump for about 3 seconds at initial key on. If you do, then, yeah, dead pump.

Mine failed pretty much the same way. Truck drove fine. Parked at home, next morning when my wife needed the truck, no start. Replaced pump, starts and runs.

 

Before going through the arduous process of replacing the fuel pump make sure the pump is really the problem. Check fuse 3 (20A) in the PDC and pin 30 at the fuel pump relay to make sure you have power for the pump. Also fuse 9 inside which is switched ignition to the relay control side. You can also try to jump pin 30 to pin 87 in the relay socket and listen if the pump runs.

That's basically the long version of doing what HeyYou suggested

 

Don't forget that pesky ASD relay.

 

The ASD relay kills power to injectors and coil but the engine runs on starting fluid so the ignition works.

 

I replaced my pump before it had a chance to fail. When i did i took the pump motor apart and it barley had any brushes/commutator left.

 

I Just tried this. Unfortunately none of these worked. it is in fact the fuel pump