What would cause an inconstant miss in a 95 geo prizm? we have changed the plugs and wires, main brain box, map sensor and the ecm. what else could it be?

95 geo prizm (rare ) is a GM re-badged,
Toyota Corolla. Gen 6 to 8
so the engine is pure TOYOTA.
super good to know this and to diagnose and buy parts vastly more easy. The engine is (or 1.6 4A)
7AFE, 1.8L DOHC EFI, gen 7 toyota design 1995
not told when did car run and drive fact perfectly
never seen it, did last week/month/decade/????????
history matters huge, for sure bad fuel ran.

getting fuel means near zero. on all EFI cars
fuel pressure matters, not dribble tests.
we use a fuel pressure gauge to measure that.
one common failure this old is bad FPR, most this old are bad.
make sure EGR main is not stuck open, seems to me not as it does idle well. so is fueling bad.
buy fuel pressure gauge, or by FPR as guess.
fuel filter must be good, not 90%^ paCKED UP.
causes of low power. right foot
low fuel pressure, bad FPR , fuel filter , pump bad
MAP sensor ,bad or more likely its vacuum port dead.
clogged gunk in map vacuum clogged. up.
the fuel filter is outside the fuel tank on frame rail ,etc.
they sell it

https://www.rockauto.com/en/catalog/geo,1995,prizm,1.8l+l4,1142019,fuel+&+air,fuel+filter,6200


FPR

https://www.rockauto.com/en/catalog/geo,1995,prizm,1.8l+l4,1142019,fuel+&+air,fuel+injection+pressure+regulator,6124


some GEOs; the gas cap fails and tank goes to huge vacuum, or a wrong cap. so start engine and run it with no gas cap at , the most easy test ever no?
no fast turns, okay, go easy.
or buy a new one, it has built in vacuum breaker inside it that MUST work.

PSI is your friend, FUEL pressure,
i read the Corolla book for you,.
key on 3 times gauge connected and see.
38-44 psi is spec, not running,
if you start the engine the FPR will drop pressure about 6 psi. (so say 40 drops to 34psi at idle)
if vacuum hose pulled off any FPR show leaking fuel the FPR is 100 % for sure bad.
but pressure testing is what matters !

code 24 ABS code or ECU coded?
OBD1 (toy)
ECU 24 is , IAT sensor wire conn, fell off. intake pipe.
Intake Air Temperature Sensor signal.(says Toy)
IAT bad never causes your symptoms.

this car has no sensors for fuel pressure
so only hand tools find the truth back then.
a fuel pressure gauge must be owned, or rented

what years? her ill give examples (no 1.8L sports)
in each case keeping original in/exh manifold of origional
this is called, a Long block swap......!
96 to 95 16v ok ( the crank sensor just sets there, doing zip)
96 to 95 8v no go. ( it will run by ECU while have fuel mapping)
95 8v to 96 16v no go ( missing crank sensor and mapping issues)
95v 16v to 96 16v,(missing crank sensor, move it.)

and you can swap any with harness and ecu. and manifolds.

see swaps here
http://www.fixkick.com/SWAPS.html#G16Bswaps

and links to near infintate swap data.

new spark wires. old wires hate, cold damp weather.
spark plugs, cap,rotor wires, try the 60k mile tuneup. per the opr.guide.
magic happens....
the map is ok.
and to test a map you need the graph and you need to compensate for altitude and local weather (barometer readings) to correct what you see.
is the check engine light glowing running?
most maps read like this, 1bar maps.
http://www.fixkick.com/sensors/my-map.html#Jeep

i bet your's is ok. the map.
your car is a toyota corolla in snake clothing.
the toy FSM covers this is find details.

93 or 95?
8v or 16valves.
ok , here are the facts.
all 8v are in the intake manifold just behind the ECT.
the 16v is always on the air cleaner box.
1992 16v the IAT is missing, that is correct. missing , on all USA kicks.

16v has 4 injectors and a MAF (apples and oranges different)

8v has 1 injector, and a MAP

der ohms.
http://www.fixkick.com/ECU/temp-sensors.html

The oil pressure sending unit will stop the pump from running. This cuts the car off if it senses no oil pressure. Same sensor that gives you the pressure reading or the dummy light.

In 1995 Geo Prizm 1.8L MFI DOHC 4cyl the MAP Sensor is located under hood, passenger side, rear engine area, mounted on upper firewall.

Hope this help.

does the vacum gauge hold steady when this is happening?

A MAP sensor problem will cause the symptoms you are experiencing. The MAP sensor is critical because you have a speed density type fuel injection system. Without the MAP sensor signal or an inaccurate one, the ECM won't know the engine load for ignition timing and fuel injection adjustments. The engine computer is detecting a high voltage condition on the MAP sensor signal circuit.
Inspect the vacuum hose going to the MAP sensor. Replace it if is looks cracked or if it collapses on itself. Make sure that the MAP sensor has vacuum by disconnecting the hose from the sensor when the engine is running and feeling for vacuum.

If you have vacuum, you can check the MAP sensor and its circuits with a multimeter. There are three wires going to the sensor. I am not sure on the colors, but Yellow should have 5 V on it with the key on. Brown is ground and should read close to 0 ohms. Light Green with a Red stripe should have 5V on it with the key on. If you backprobe the MAP sensor connector with it plugged into the MAP sensor on the light green/red wire and apply vacuum to the sensor, the voltage should drop.

check crank sensor.

use an electrical tester with a sharp point tip, and poke through the coating into the wire at every 5".

this is the best wat to test the wiring.