Hi! my 1996 blazer 4.3 engine, suddenly stop and now only start if I use starter fluid directly to carb system. please advice.

 

I've recently had a similar issue. After changing almost every fuel and Ignition component in the vehicle, I found a $25 ECU at a Junkyard in town, slapped it in, now it starts up every time. Look around, try and change the ECU with a used one that still works, if that doesn't work it might be something with ignition, or the Central Port Injection System.