Does anyone know what the stall speed for the torque converter of a 96 3.0 is supposed to be? The transmission is a 4R44E. Right now I’m stalling at 2200-2300 rpm. I’m having a serious lack of power, and i I’ve got 3 cylinder misfire codes and a system too lean bank 2 code, but it only throws those codes once I put it in Drive and/or Reverse. I’m really at my wits end with this and so I figured you guys were the ones to ask.

 

Welcome to the forum

Seems a little low for the 3.0l Vulcan engine, closer to 2,800 would be spec

The codes are the lack of power not stall speed
3 misfire codes is HALF the V6 engine not working so...............yes that would cause lack of power

What are the exact codes, there are literally HUNDREDS for the same thing, each with slightly different meaning.

Full list here: https://therangerstation.com/tech_li...II_codes.shtml

Clogged exhaust will cause misfires and lean codes
Low fuel pressure as well
Dirty MAF sensor
Vacuum leak
Failing O2 sensor on one bank

 

P0301 Cylinder 1 Misfire
P0302 Cylinder 2 Misfire
P0306 Cylinder 6 Misfire
P0174 System Too Lean Bank 2

I get what your saying. The main reason I’ve been thinking torque converter is because of the shuttering and rough shift, plus slippage. But I suppose I should worry about fixing the code issues first and go from there.

 

Cylinders 1 and 2 are on Bank 1, passenger side of engine
Cylinder 6 is on Bank 2, drivers side

Cylinders 2 and 6 share one coil in the coil pack, so new coil pack "may" be a place to start assuming you have pulled out spark plugs and cleaned/gapped or replaced them

"Lean" in engine computer language means computer is opening fuel injectors longer than it calculated to get O2 sensor voltage into correct range, in this case just on bank 2(cylinders 4, 5, and 6 injectors)

O2 sensors detect Oxygen in the exhaust, they generate their own voltage, and have a voltage range of .1 to .9 so under 1 volt

.1 volt means high oxygen, we call this lean
.9 volt means low oxygen, we call this rich

Computer adjusts fuel injector open time to keep (upstream) O2 voltage at .4 volt

An engine works by burning gasoline using the oxygen in the air, causing an explosion to push piston down
If there is no explosion, a misfire, then no oxygen is burned/used and that oxygen is dumped into the exhaust, where O2 sensor sees it as high oxygen, .1 volt
So computer adds more fuel because O2 shows "lean", high oxygen

A vacuum leak is an air leak, all air coming into the engine should pass thru the MAF(mass air flow) sensor, computer bases its injector open time on the amount of air coming in.
If there is "unreported air", a leak, then computers calculation will be off, so computer set a lean code in that case
BUT................it would be for BOTH banks, if it was a larger vacuum leak, a lower intake leak on bank 2 side could cause misfire #6 and lean code on that bank

Dirty fuel injectors have a reduced flow of fuel when they are open, computer bases its calculations on the size of injector and fuel pressure, both programmed into the computer at the factory, it has no way to monitor these parameters
So run a can of Seafoam or similar injector cleaner in the gas tank, I do this once a year

O2 sensors usually last 100k miles, then they run out of the chemicals to generate the electrical current, so are always showing low voltage, .1 volt, this causes "false lean" and a drop in MPG, and can cause misfires by fouling spark plugs with a Rich fuel mix, you would see darker color brown on spark plug tips

An exhaust manifold leak SUCKS IN air, this also causes a "false lean", so if you hear an exhaust leak at the engine then air is being sucked in

 

Now that you mention it, I do have a darker brown color on my spark plugs. I’ll definitely run the Seafoam as well. Is there any way to test an O2 sensor? Maybe check voltage with the vehicle running?

 

No, not really, O2 voltage output tells you the oxygen level in exhaust and that's adjusted by fuel mix from computer, so................voltage would be correct but mix is actually too Rich because O2 sensor is old

If there is more than 80k miles on them then just change them on speculation, they pay for themselves in better MPG over their life time

Misfires also cause Rich running because no oxygen is burned up, so there are other issues, O2 sensor replacement won't fix

 

Oh I understand. Well I really appreciate the help man. I’m gonna give it a go. Will post results here once it’s done.