1991 Ranger 2.3 is sputtering at about 1500 rpms in whatever gear unless your cruising...especially when climbing hills in 3rd gear around 25mph and 1500 rpms or when taking off. Changed the coil, wires, plugs, and fuel filter and its still doing it..what else could be causing this only around low rpms or when under load? It like a slight missfire and just feels like the truck jumps a little and regains power after a half a second. I've tested a little bit.. So I unplugged the maf to let it go to the stock air fuel mixture.. It was better but not perfect.. So I plugged it back in and unplugged the Tps and it was better running than the other but not perfect.. I am wondering if it is a mix of the two??

Here is a video to explain a little more. The video was also before I started unplugging sensors. It just sputters every now and then with either one of the two and not like that.
https://vid.me/9sCm

Edit: I also forgot to say that I used auto lite copper spark plugs because the parts store I used to work at said they were copped but looking around the forum it looks like maybe it's platinum?? Although the plugs I took out of it were auto lite coppers and they seemed to run great and fine.. So I'm confused :)

 

Welcome to the forum

And just to confirm, running at 2,000rpm and up engine is fine, right?

And just for the record the 2.3l is a high RPM engine, it doesn't reach max torque until 2,600rpm and max horse power at 4,600rpm
So at 1,500rpm it won't have much power.

Get a volt meter, $25, will save you hundreds in replacing the wrong parts.

Get a couple of sewing pins to pierce wires to test them live.

Put a pin in the middle wire on the TPS.
Turn key on, engine off
Set meter to DC volts
Ground meter
Put Red meter probe on pin
You should see .69-.99 volts, under 1 volt
Now manually open throttle and do it slowly
Voltage should start going up
It should be above 4.5volts at wide open throttle

But what you are looking for are dead spots or spots where volts jumps up
It needs to be a nice and steady up or down voltage
If it jumps around computer thinks you are tapping on the gas pedal, so you get jerky operation at that spot in the throttle.

MAF sensor will have 4 wires
These two power the MAF
Red is 12volts
Black/white stripe is Ground

These two are for computer to read air flow.
Tan/blue
Blue/red

Use pins to pierce tan and blue wires, put them far enough apart so they can't short together.

Start engine and let idle.
Hook meter to pins, if you get -volts reverse probes on pins
You should see under 1 volt, if engine is cold and idle is high then could be just over 1 volt
But it should be steady if RPMs are steady.
Raise RPMs and voltage should increase as air flow into engine increases
Voltage should be steady at any set RPM,
voltage will go up and down with RPM but should be steady if RPMs are.

At 6,000 RPM voltage should be just over 4 volts, you don't need to test that, lol, but you can :)

 

Yes roughly 2000-2500 and lower is when it does it.. And it idles fine.. I know that about the 2.3 but it never did it before until recently.. It's always been hard getting up hills but not sputtering and jumping like in the video

 

I know you last posted 4 weeks ago on this thread,but did you get the issue resolved?? If not,the ignition module & a egr valve thats sticking open/closed can cause your symptoms.Autozone can test the module if you remove it & bring it in.
You can remove the egr vacuum hose,at startup while idling,to make sure that hose doesnt have vacuum at idle.If it does,the evr solenoid is usually at fault.If that hose does have vacuum, at idle,& you reconnect it to the egr valve & the engine doesnt stumble or stall,the egr valve is likely sticking or the diaphram may have a pinhole leak in it,which will cause a vacuum leak.When vacuum is present at that hose & you connect it to the egr valve,the engine should stumble or die if the egr valve is functioning properly.
I had the same symptoms as you're having and I disconnected and plugged the egr valve vacuum hose & the symptoms disappeared.