I have a 1999 Dodge Dakota 3.9L V6 automatice 4X4 that refuses to start.

eather the fuel pump has gone out or the pickup in dis is bad.when you turn the keyswitch on,do you here a humming for about 3 seconds from under the truck,if not,fuel pump.

Have you hooked up an OBDII code reader to see if there are any codes. It could possibly be a mapp sensor.

First thing I would do it listen for the fuel pump as was mentioned... after that check the pressure at the fuel rail, you should have 45-50lbs. After that I would start to suspect the ignition, just be cause you can see spark when testing doesn't mean it's strong enough to ignite the fuel mixture under compression or that the spark is in time. The ignition coil, cam sensor (pick up coil), or crank sensor could all cause your problem without throwing a DTC