iv got a 91 blazer 4.3 tbi, it ran great when i drove it 2 see my girlfriend 1 day, until the battery died. the battery died and it wouldnt hold a charge so i would have 2 jump it off. then 1 nyte after jumping the truck off 2 leave my buddies house the truck cuts of and it wont start up. i replaced the battery, and when i did i found that my distributor had come loose. check the ignition coil and it was bad so i replaced it along with new plugs and wires and still no start. and i have already read the thread about egine cranking but no start but i was just looking 4 some other feed back. i have spark i tested visually with crank it with a plug connected 2 a wire but outside of the block, i hear the fuel pump kick on and i can see the injectors spraying while turning over, and the timing chain isnt broken. iv checked the normal things i know to check i really would appreciate some help cause i miss and need my truck.

 

and i also replaced the distributor cap and rotor button a week or 2 before this started happening.

 

if the distributor was loose, then maybe your timing is off, have you checked it with a timing light? (i can't remember but maybe someone can help me, sometimes you have to disconnect a little brown wire on them to get the timing to work right) but also on those the little control module attached to the distributor were notorious for going bad. What happens is the thermal grease on them dries up and won't transfer heat as well. so check that little module if the timing won't work.