OK I have a ranger that's a 2.5 4cyl and it has this problem that only occurs randomly one min you can cruise or hammer it the next it loses power drops speed and if you hold the pedal down it backfires sputters and jerks . And only way to fix it is to downshift and floor it but it will do it a few more times before stopping it I can't get one the highway at all with it doing this. Please help me . I'm at wit's end here new plug wires was installed justa little bit ago mileage 300k new clutch and master cylinder no cel either

 

Welcome to the forum

1998 to 2001 Ranger I assume???

2WD most likely
Manual or automatic?

2.5l didn't have many changes for those 3 years so I guess that shouldn't matter.

Couple of things come to mind
Fuel pump is failing, so you are losing fuel pressure then getting it back

Cat Converter or Muffler has broken up inside, so exhaust is being blocked then opening again.

Both would cause those symptoms without turning on the CEL(check engine light)

Make sure CEL is working, it should come one with the key, shows computer is booting up, and then it will go off.

If CEL is not working then swing buy an auto parts store and have them hook up a scanner to read any codes, WRITE THEM DOWN.
And don't buy anything post them here first

 

Cat has been sliced off and yeah it's a manual and a 98 ext cab ac no cruise . But I didn't think a fuel pump could do that I always assumed they just quit or wouldn't allow you to move not make it backfire and lose speed . If you baby it around town it does better but will at some point do it too then as well but recovers more quickly

 

Did you change the fuel filter?

 

Original fuel filter I've only had the truck for a week at most

 

Might want to check your spark plugs/ wires.

 

Already did those are in good shape coil packs too . Though I forgot to mention when it does it in city flooring it helps it come out of it.

 

1998 Ranger should be running Returnless fuel system, so 65psi fuel pressure
Yes, fuel pump problem or clogging fuel filter can cause lower pressure as demand goes up(higher RPM/Load).

Computer has no way to monitor fuel pressure so it won't cause CEL or code
But over time you can get Lean code with lower pressure.

What did the tips of the old spark plugs look like?
light brown/white is correct burn color
Darker brown/blackish means Rich burn/running
If they did show blackish color then upstream O2 sensor may now be bad, pull it out and have a look, if it is blackish as well the replace it.
And thats probably why Cat was removed, previous Rich running killed it

You didn't answer if CEL works, comes on with the key?

Computer is programmed for a 2.5 LITER engine so it knows how much air should be coming in at any given RPM and throttle position(load)
But it also relies on the MAF(mass air flow) sensor to fine tune that, MAF also compensates for altitude above sea level.
MAF works by heating a wire and seeing how fast it cools off from the air flow, pretty simple device and works well unless it gets dirty
Easy to clean the MAF with MAF Cleaner spray or other electronic spray cleaner that doesn't leave a residue.

TPS(throttle position sensor) is on the upper intake and fairly easy to test with volt meter.
Computer sends TPS 5 volts
Inside the TPS is a variable resistor like a light dimmer or volume control
If TPS sends under 1 volt back to computer then computer knows throttle is closed, .69-.99volts is spec
If TPS sends computer over 4.5volts then computer knows throttle is wide open(WOT), 4.50-4.99 is spec
Voltage in between is throttle position and needs to be stable or computer would think you are feathering the pedal.
You can pierce the center wire(volts back to computer) with a sewing pin, turn on the key(engine off) and you should see under 1 volt
Then open throttle manually while watching the voltage go up, should be nice and steady, no jumping up or down, until at WOT which should be at or above 4.50 volt

TPS do wear out, moving part and all

But........MAF and TPS are both monitored systems, it is possible for a failure not to set a code and turn on the CEL, longshot but possible


just for reference
When you cold start any fuel injected engine, don't touch the gas pedal
Engine should start and RPMs should go up above 1,500, IAC Valve fully open
Then RPMs will drop to about 1,100-1,200(IAC Valve closes to set cold engine idle), depends on outside temp, Computer is running Choke mode, Rich fuel mix, high idle, advanced spark timing
As engine warms up the idle RPMs will slowly decrease, ECT(engine coolant temp) sensor warms up and computer closes IAC Valve a bit more as it does.
When fully warmed up(ECT shows above 180degF) manual trans vehicle should idle at 650-750rpms, 4cyl are probably closer to 750

If your truck doesn't follow this then that could be a symptom

 

I regret and stupidly admit myself that I honestly forgot to look at the plugs when I swapped them out for new ones but the cel does light up when you turn the key on just doesn't stay on like if there was a code or anything . This truck idles at 1k at warm temp the inside temp gauge is very very slow to come up to op or move for awhile . I'll remove the 02 and see what that looks like if it's like omg black or normal but I'm honestly wondering if it is my fuel pump

 

Reads like your thermostat is remaining partially open, not a big deal but will take engine longer to warm up so cost you $$ in MPG.
To test for this pop the hood and start cold engine.
Feel upper radiator hose, should be cold.
Wait 2 or 3 minutes and feel it again, should still be stone cold
If it is warming up with the engine that means thermostat is open and allowing coolant to flow thru radiator.
Radiator is there to get rid of EXTRA heat, point of the thermostat is to decide when there IS extra heat to get rid of.
Fords use 190-195deg thermostats, in colder climates 205deg thermostats are often used.
The 4cyl Lima engines don't generate alot of heat, so when outside temps are below freezing the radiator often doesn't/shouldn't even warm up.
People often put cardboard in front of the rad in the winter to reduce air flow into engine bay just to keep these engines at operating temp, 195-220degF


Test for vacuum leak, warm idle above 800rpm means you probably have one
After engine is warmed up and idling
Unplug the 2 wire connector on IAC Valve
It will close all the way and idle should drop to 500rpm or engine might stall, either is good it means no vacuum leak.

If idle stays above 700 then start pulling off vacuum hoses from intake, 1 at a time, and plug the port with your finger, if RPMs drop then you found the hose with the leak

One other thing if idle stays high, on the throttle linkage, where gas pedal cable connects, there will be a screw that "looks like" an idle screw, fuel injected engines can use an idle screw because there are NO JETS, so air flow into engine needs to be set by the computer via IAC Valve, so not "user adjustable", lol.
The screw is an anti-diesel screw, but if someone adjusted it then it could cause the higher idle AND throw off TPS(throttle position sensor) voltage.
So with engine warmed up and idling, and IAC Valve disconnected from power, unscrew this screw a 1/2 turn and see if idle drops, if it does then someone has been messing with it.
Keep unscrewing it until idle is below 600 or engine starts to stall out, then don't touch it again, and that was the problem, not a vacuum leak