YES!!!! are they all not firing or are 1 and 4 just firing and 2 and 3 not firing or vice versa. that's EXACTLY what happened to me when i did my timing for the first time. my car would crank all day then every once in a while it would make a nice big back fire fart. here is a thread that i posted about a month ago, this may give you the answers you need or atleast help you not ask the same questions that i did. good luck dude. :thumbsup
http://forums.2gnt.com/dcboard.php?az=show_topic&forum=5&topic_id=61821&mesg_id=61821&listing_type=search