I am helping my brother try to diagnose his 92 Ranger 2.3L run problem. My name is Charlotte, and I have worked the automotive industry 40 plus years, mostly in heavy duty and off road equipment as a shop owner/operator. Closed our shop in 2009 because of the economy. Worked for O'Reilly Auto Parts as an Installer Service Specilist (ie commercial customer sales) from 2008 to 2014 when I retired. I am far from a mechanic, but have a decent knowledge of the gas and diesel engine.
My brother's 92 Ford Ranger 2.3L will start, idle and even go up his driveway, but when he accelerates and goes onto the road it hesitates, backfires and dies. He has had the EGR valve changed, tuned complete with plugs, wires, coil packs, air filter, fuel filter, module, and MAF sensor. No change. What are we missing.

 

Welcome to the forum

Can you REV the engine when not moving?

I assume the CEL(check engine light) works, comes on with key on and then goes off after engine starts?
And its not on after engine is started so no trouble codes?

If that's true then its a mechanical issue, so probably not spark or sensor related

Could be low fuel pressure, Rangers never had a fuel pressure sensor, there is a fuel pressure test port on Fuel Rail of the engine, looks like a tire's air valve because it is, its a schrader valve, works the same way, you can rent fuel pressure test gauges, but they are not expensive
Running pressure should be 30-40psi

Fuel pressure is created by the fuel pump but it can supply 80psi, so there is a Fuel Pressure Regulator(FPR) on the engine set for 40psi, it has the Return fuel line attached AND a vacuum hose
Those are the two things that hold fuel pressure in the system
Key off pressure should hold above 15psi for a few MONTHS, just FYI

Partially Clogged exhaust, not uncommon for Cats and muffles to break apart inside, pull out the O2 sensor so exhaust has a way out, then try a test drive, it will be LOUD, lol, but if it runs much better then exhaust IS clogged
You can also test for that with Vacuum gauge, hook up gauge, start engine
should see 17-20" of vacuum
Raise RPM to about 2,000, exact doesn't matter just high RPMs and hold it there, watch gauge vacuum will drop then come back up if exhaust is clear, if its slowing dropping then exhaust is clogged
REV engine, quick "blip" of throttle, wide OPEN then let it snap closed, should see a drop to under 5" then a QUICK return to 20" or so, if slow the clogged exhaust