95 Chevy S-10 Blazer won't start unless i use starting fluid

I have a 1995 chevy blazer s-10, 4.3 Vortec CMFI 4X4 that i purchased about a year ago, my son drove it for about 8 months, then it started bogging down & had a miss in it, i took it to auto zone to have the codes read, the engine light will blink when started then go on steady, they advised i had a miss in cylinder 4 & a bad 02 Censor, When i purchased the vehicle i replace the Distributor, rotor, cap, plugs, wires, was running good, then the engine light came on, took it to auto zone, they advised the 02 sensor, Throttle position sensor, miss in cylinder 4, replaced the Throttle Pos Sensor, had a mechanic look at it, he advised was the Spider Assembly, recently replaced that & added a new fuel pump & fuel filter, now the truck will only start when i use starting fluid, after it's running it doesn't stall, but if you try to rev the rpm's up past 2 to 3 thousand, it sounds like it is backfiring. Also I have removed the catalytic converter. I have had a ton of back surgeries & tired of spending a ton of money on mechanics, does anyone have any idea's on this damn thing? any help would be greatlt appreciated.

Have the catalytic converters checked, a plugged cat will choke your engine out, and has the
the same symptoms., but starving for air instead of fuel.

sorry i should have mentioned, that the Cat Converter has been removed

When it starts if you add starting fluid, (not a good idea, use carb spray) that's a classic symptom of low fuel pressure. Check fuel pressure and leakdown. CMFI only: Key on, engine off, fuel pump running: Pressure must be 58psi to 64psi and must remain above 53psi for 3 to 5 minutes after the fuel pump shuts off. If you installed an aftermarket fuel pump, chances are that's the problem.

As for the misfire, stick with AC Delco plugs, cap and rotor. Put a dab of silicone dielectric grease on each terminal, inside and out, of the cap. Don't waste your time or money on Duralast, it's not durable, and it doesn't last. AC Delco cap & rotor are good for 100,000 miles, Duralast maybe 30,000, if you're lucky.

If the converter has be removed, eventually the check engine light will come on and set a DTC, (Diagnostic Trouble Code).

What was the Brand name of the Distributor you installed? Wasn't an Airtex Distributor by chance was it? I had to replace the Distributor in my 2001 S-10. I let someone talk me into an Airtex Distributor, complete with a cap. The cap was pure SHIT. The cap lasted 6 months before it shorted out internally and misfired so bad the truck wouldn't run.

Anything but an AC-Delco Cap and Rotor will simply not last in these trucks. Don't listen to ANY Parts Counter Expert, Their Home Grown Cap is NOT, NOT, NOT as good or better than an AC-Delco cap. Even if you have to wait a day while they order you an AC-Delco Cap in, PLEASE do your self a favor and wait for the AC-Delco Cap and Rotor. You'll thank me later.