My 2000 chevy blazer 4×4 4.3 vortec wont start after i changed map sensor. But i touched map wires together on misyake bcuz i didnt tape off bare wires yet... since then my blazer just wont start... it wont start when i use starter fluid either. Fuel pump turns on but i dnt thibk its getting the initial spark

SOURCE: have a 1994 chevy s10

You need to check and make sure you have fuel pressure, then check for spark at ignition, if those check out then check for pulse width at the injectors. That basically is the electrical signal which tells injectors to spray fuel. Use what is called a Noid light on injector pulse width check. that will eliminate all possibilities other than internal issues with engine. I.E. broken cam, broken timing components, obviously if all I mentioned checks out then run compression test. Good Luck

SOURCE: 2000 chevy blazer wont start overheated and now wont start

This model has a problem with the fuel injectors and the fuel pressure regulator, its under the intake manifold, one peice unit...getting fuel in the engine.....how do ya know...wait did you change the plugs after it would not start?...re check the wires might be wrong firing order

SOURCE: 1999 chevy blazer wont start

THE FUEL PUMP IS BAD.

if your losing fuel pressure after the pump runs the drain back valve in the pump has failed.

and i doubt that you are seeing enough fuel pressure to run a vortec engine.

low fuel pressure equals a non running vortec

SOURCE: 1997 Chevy Blazer wont start without starter fluid

Check fuel pressure it could be low regulator pressure

SOURCE: 2000 chevy venture doesnt start

Not the IAC, or MAF, or 02

Does the Van Crank over?
Have you checked the IGN Relays? 1,2,and 3?
How did the Battery test out?
Anything below 11.9v battery is dead.
So I suggest that you do not throw any more parts and check the battery again.