2.3L ('83-'97) ‘97 2.3 very poor throttle response

[Dylswhitetruck97]

Hello Ranger gurus, I’m new to the forum and I’ve got some questions about my ‘97 Ranger. It’s a 2wd xlt 2.3L 5-speed. It’s my daily driver and runs fine for the most part, but has terrible throttle response. If I don’t carefully and slowly apply the throttle the engine will “cough” or stumble. It still seems to run ok at wot but feels a little sluggish. Has new plugs and wires, adequate fuel pressure, new fuel filter, just cleaned the maf sensor, just wondering if anyone else has had a similar issue as the truck is not very pleasant to shift through the gears. Gotta ease into the gas to avoid a short little misfire. Otherwise it idles fine and doesn’t misfire in the general sense. Will greatly appreciate feedback as I’ve just dealt with the issue for awhile

 

[Shran]

What do you mean by adequate fuel pressure - have you tested it with a gauge? Weak pumps will sometimes supply enough fuel to run at idle or light load but when more is needed it will lean out and do what you are describing.

 

[RonD]

Welcome to TRS

With the limited data I would say TPS(throttle position sensor) issue

I would buy a $15 Bluetooth OBD2 reader, and $5 Torque Pro APP
You can then SEE all the sensors the computer uses in real time
Then you can see if the TPS is working correctly

You can also see if the spark timing is correct for acceleration

TPS is fuel injection's equivalent of the Accelerator Pump in a Carburetor
When driver presses gas pedal down computer sees that and adds more fuel instantly
MAF sensor is to slow to respond to instant air flow changes
So without good TPS data engine will stumble on acceleration but will eventually recover as RPMs steady out

Spark Advance also needs to change when fuel mix changes, i.e. accelerating should be a Richer fuel mix, if spark timing is off then stumbling until RPMs and fuel mix steady out
Vacuum Advance on a distributor did this in the bad ol' days


The $15 Bluetooth OBD2 reader will save you $$$ because you don't need to swap sensors "just to see" if that's the problem
And these work on ANY vehicle sold in the US/Canada from 1996 thru 2024, its the Law, not a Ford or even US car maker thing, ANY vehicle

O2 sensors need to be changed every 12 years or 100k miles
So just a heads up, they are THE ONLY sensors that wear out on a schedule

 

[CamTheHedgehog]

O2 sensors need to be changed every 12 years or 100k miles
So just a heads up, they are THE ONLY sensors that wear out on a schedule

I totally didn't just recently change the original O2s in my 2003 with 250k...

shhhhhhh.......

 

[RonD]

Hey its your money going out the tail pipe

 

[CamTheHedgehog]

Hey its your money doing out the tail pipe

It does seem to run smoother though. Haven't driven it enough to give a definitive opinion on fuel economy.

 

[scotts90ranger]

Yeah, at least pre cat O2 would be recommended, but it could be something dumb like the cam sensor pulley not lined up right, had a timing belt done anytime recently? My '97 has 210k miles on it and it seems to run just fine and does none of that, there's a mild surge here and there at like 30mph and sure it doesn't have much power but it holds it's own.

There's something goofy going on...

 

[Dylswhitetruck97]

What do you mean by adequate fuel pressure - have you tested it with a gauge? Weak pumps will sometimes supply enough fuel to run at idle or light load but when more is needed it will lean out and do what you are describing.

Checked it couple months back and the pump had 38-40psi at idle

 

[Dylswhitetruck97]

Yeah, at least pre cat O2 would be recommended, but it could be something dumb like the cam sensor pulley not lined up right, had a timing belt done anytime recently? My '97 has 210k miles on it and it seems to run just fine and does none of that, there's a mild surge here and there at like 30mph and sure it doesn't have much power but it holds it's own.

There's something goofy going on...

I changed my timing belt in May of 2021. That was a pain because when I went to replace everything I realized I had no timing belt tensioner spring. I was told by all the parts stores that they don’t carry that item, only genuine Ford springs exist. So I paid around $80 for a stupid little spring!

 

[Dylswhitetruck97]

Welcome to TRS

With the limited data I would say TPS(throttle position sensor) issue

I would buy a $15 Bluetooth OBD2 reader, and $5 Torque Pro APP
You can then SEE all the sensors the computer uses in real time
Then you can see if the TPS is working correctly

You can also see if the spark timing is correct for acceleration

TPS is fuel injection's equivalent of the Accelerator Pump in a Carburetor
When driver presses gas pedal down computer sees that and adds more fuel instantly
MAF sensor is to slow to respond to instant air flow changes
So without good TPS data engine will stumble on acceleration but will eventually recover as RPMs steady out

Spark Advance also needs to change when fuel mix changes, i.e. accelerating should be a Richer fuel mix, if spark timing is off then stumbling until RPMs and fuel mix steady out
Vacuum Advance on a distributor did this in the bad ol' days


The $15 Bluetooth OBD2 reader will save you $$$ because you don't need to swap sensors "just to see" if that's the problem
And these work on ANY vehicle sold in the US/Canada from 1996 thru 2024, its the Law, not a Ford or even US car maker thing, ANY vehicle

O2 sensors need to be changed every 12 years or 100k miles
So just a heads up, they are THE ONLY sensors that wear out on a schedule

Thanks Ron, I’m not real tech savvy so your advice is very helpful! I’m definitely gonna try that OBD2 reader and torque pro app

 

[Shran]

Checked it couple months back and the pump had 38-40psi at idle

What was it when you blip the throttle - should go a little higher. Last one I was fighting with showed pressure within specs at idle but it would drop down to mid 20's when the regulator opens up.

I changed my timing belt in May of 2021. That was a pain because when I went to replace everything I realized I had no timing belt tensioner spring. I was told by all the parts stores that they don’t carry that item, only genuine Ford springs exist. So I paid around $80 for a stupid little spring!

Was this problem present before your belt change or did it start afterward? Possible you didn't get the timing marks lined up? I did that, cam was a tooth or two off. Ran OK but had no power. Took me a while to figure out why.

 

[Dylswhitetruck97]

What was it when you blip the throttle - should go a little higher. Last one I was fighting with showed pressure within specs at idle but it would drop down to mid 20's when the regulator opens up.



Was this problem present before your belt change or did it start afterward? Possible you didn't get the timing marks lined up? I did that, cam was a tooth or two off. Ran OK but had no power. Took me a while to figure out why.

Before the belt change. I bought the truck 4 years ago non running for cheap and all it needed was a maf sensor. The throttle response issue has always been a characteristic of the truck since owning it.

 

[Dylswhitetruck97]

Welp turns out I have a dead oxygen sensor