Assuming that S10 has a 4.3 L engine with TBI (Throttle Body Injection), the fuel injectors (two of them) are located in the throttle body.
This is confusing, a 1998 does not have a carb.
The fuel cutoff switch, on your 1998 Chevrolet Blazer, can be found on top of the fuel injector pump. The fuel injector pump is on the back side of the engine near the top.
Answeron the injector rail...follow the fuel hoses from the tank to the enginedThe Regulator it under the upper intake on the injector
It is under the upper intake manifold, attached to the bank of poppets.
if its a cpi it would be in the the middle of the intake as part of a injector assembly on a 4.3L
The engine will develop a skip and the check engine light will illuminate. The code set in the ecm will direct you to which injector is bad.
The 1985 Chevrolet S 10 blazer fuel pressure regulator can be found on the top of the engine. The fuel pressure regulator will be near the fuel injector pump.
If you have spark at the spark plug, it is probably a bad fuel injector.
It will be a 305 or a 350 fuel enjection engine ( TBI )
on the top of the intake manifold next to the main injector
The ecm does with input from various sensors.