It all started a few weeks ago. A couple of times the damn truck just stopped running, no warning, just quit. Started okay with a bit of cranking. Did notice the warning lights (ABS, Seatbelt and others) didn't come on for a few seconds. Once the warning lights came on it started. Now the truck is sitting in my garage, it'll crank til the cows come home but she won't fire. I can hear the fuel pump come on. But there are no warning lights coming on. No ABS, no seatbelt, no oil lamp nothing. The radio, fan, engine temperature, oil pressure gauge, exterior temperature gauge all work, she just cranks and won't fire. The key works fine, on, off, accessories, remove, no problems. Also, I can't get the shifter to come out of park as it seems the lock thingy won't let me shift. What the heck could cause all this? As it is, I have the stupid truck stuck in my garage and I can't even pull it out as I can't get it into neutral. Very frustrating. 4.3L Jimmy but I think the Blazer is basically the same. Any ideas or similar problems?

 

Check if your plug wires are all connected and have your fuel pressure tested...
Maybe a bad coil?
Once, my truck was dying on me every now and then, and it was two bad plug wires...
My $.02...

 

"I can't get the shifter to come out of park "

I would check into the shifter problem by doing a search on this site. It may be that whatever is keeping you from shifting is also stoping the truck from starting because the truck thinks it is not in park.

 

Had a similar problem just a few months ago.

I have a '97 with almost 180,000 miles on it.

It wouldn't do anything until all my gauge lights came on and I heard the beep when you first turn the key. It would take a few seconds, then when all my indicator lights came on, I'd hear that Blazer beep, then it would fire right up. The dealership put a new ignition switch in and it was fine. About $300 bucks!

 

That last post has it pegged, in my belief. The ignition is not coming on properly. Now this may be due to the ignition switch or one of several relays not operating. Check all fuses. Check a book and see which/what relay(s) operate when switch comes on. Check all 12v and ground connections to these relays.

It is certainly possible for the igniton switch or a relay to be acting up. I would not take it to have the switch replace without checking the book. The Haynes manual has just about enough info to actually change your own ignition switch if you need to.