Help! Broke down Dakota

Like the title says...
My son is about 100 miles away in another city. He just called and said that his Dakota, 1998 V-6, has quit running, in the middle of the road of course.
The truck will restart, but only idle at about 500 rpm and then slowly dies. After starting if he gives it any gas it immediately quits.
Please shoot me a suggestion of where to start with this.
Thanks,
C