97 2.3 Stuttering

[Nitebot]

Back ground I have a 97 2.3 Ranger manual, about 100k on it.
Been a wonderful vechile to be fair..But as late i am having an issue and i need help.

When ever i am driving and either get around 30 plus mph or the truck gets under load , say shiftin to 3rd gear or so..It bucks sputters stutters and will die if i dont pump the gas pedal.

It threw a few codes at me that i've sense fixed up. (misfire and o2 sensor)

Yet its still doing the same thing.

Idles great smooth as silk. Even crank it up to 6k rmps and it runs smooth.Only when driving does seem to sputter.

What i've done thus far.


Fuel Filters ( 2 of them )
Fuel Pump
All injectors checked
Fuel reg checked.

New battery
Egr valve
Egr sensor
tps ( 2 of them )
iac ( 2 of them )
o2 ( new..then..unpluged to see if that would be the problem )

Wires
plugs
new coils packs.
Mass air flow sensor ( 2 of them ).

I've cleaned the throttle body.
Checked for vacuum leaks ..basicly taken each hose i can get to off, put them under water with air running them them.

Someone suggested that the alternator could be the problem. So i will take that off and get it checked this week.


Any ideas suggestions guys only have so much hair left at this point and thats turningg grey. lol.
Should have taken it in , but i felt i could do it myself. Dumb huh ?

Thanks in advance .

 

[klingon20]

Once you have this figured out you will know your vehicle very well, cudos for hanging in there with it, check to make sure your getting good back pressure and the cat isnt taking a dump.
Re-check all your electricle connections and use dilectric grease or spray to ensure you are getting good contact and this will also help with any future moister issues.

 

[blisted]

Id concur to take a peak at the Cat

 

[LivinTheDream]

Me Tooooo!

I have the same problem. I have a 96 Ranger. It idles fine but then only while driving does it sputter and buck. But let me describe it better. The engine does not just lose power, it bucks hard. It feels like a kill witch is being turned on and off. Then when you let your foot off the gas and back on… the problem is solved until anther minute or so. Sometimes it drives fine for 20 minutes with out bucking. Other times it bucks in every gear.

I don't know where to start.

Also the engine light flickers when it bucks but never holds a code. The light just flickers when it bucks.

 

[Nitebot]

One of the items i forgot to list was a new Cat. Sorry.

Thanks guys for the advice i'll do that this week as well, see if there is improvement.

No kidding i'll know every part of this truck at this rate lol.

 

[blisted]

Muffler maybe?? Could have some restriction in the exhaust causing some of those issues. I am about to replace my cat for a similar issue.

 

[Nitebot]

Dropped the whole exhaust system, all seems well with it.

Still have the same problem. Have yet to take the alternator to check it.

Did the electric recheck..All seems well there too.

I am beging to wonder if the computer is trashed.?

Any ideas?

 

[Funnyman141]

do you have a plastic tank or a metal one?
does it do it while going up hills and after fast take-off then you might have something in the tank clogging up the pickup sock

 

[Nitebot]

Plastic tank.

only seems to do it under load..Example changing gears from 2nd to 3rd with low rmps.Somtimes even high rpms. Mainly anytime the motor is forced to work a bit harder than idle. No Hills here soo couldn't tell you.
Pumping the peddle keeps the truck running.
Its like the power drops off to half and its needs Air or Gas.

I've have been thinking about dropping the tank again just to check the pump.


IDLE runs smooth. Gas pressure seems stable..I not sure how to test while driving however sooooo.

 

[ZackB]

I would check all of the grounds, there was a post here recently about the ground to the ECU. A bad ground there would cause stuttering as you described.

 

[Nitebot]

Really ? hmm i'll do that. Couldnt hurt at this point.

 

[Nitebot]

Update:
Alt is good, grounds good. Not much left on the truck to check.
PCM ?
Short of replacing the fuel system.

To be honest tired of throwing money and time at it blindly .

 

[blisted]

You said cat was replaced but was the exhaust checked at the muffler? Could be clogged from previous bad cat, causing some backpressure.

 

[Nitebot]

Yes sir, i've even dropped the whole thing and ran it without cat and muffler to test it out..