sometimes? what is the problem? it stalls and dies, and sometimes its hard to start and sometimes it starts with no problem... its a 4.0 inline 6. it backfired, but thats not the major problem. The main issue is no matter the speed it kills like there is no gas or no spark. what do you all think is the matter??? I have changed the sparked plugs, cleaned rotor, cleaned the distributor cap, and cleaned throttle valve body, and still nothing works. I would appreciate it if anyone would suggest anything else or if anyone has had this problem before... thanks!