Bad milage/ecu code/low power

[bsskibum]

1992 pathy a/t 4x4 v30e

 

So I finnaly got the new tranny installed and the truck pulled out on its own..

see video here.. http://www.youtube.com/watch?v=ghFonE8U36k...feature=channel

 

I bought this truck with the full knowledge it had a tranny issue(tranny got really hot,b4 I bought it, and wouldnt move anymore) Once I got the tranny out realized the splines for the oil pump in the torque converter where gone, smoothed out. Who really knows what happened but I bet a clog of tranny fluid lead to a heat issue, then it siezed and stripped torque converter splines.

 

Well anyways, I was never able to drive it and see if it had other issues..The guy i bought it from is a look good . not a mech sound vehicle.

So now it runs.. well kinda.. thus why I have created this topic

 

Heres the QUESTION...

I start the truck idles fine.

I put it in gear(man she shifts nicely )

and push on gas... and under a load it gets going but it feels like the engine is missing...

once you get to about 2400 it starts pulsing

the power the truck has is not as my friends pathy.

I did the ecu codes.. and got back a 34 (knock sensor)

contacted Casey.T about location and for pics which he graciously provided..

I now read on the forum the o2 sensor could also cause this problem and cause engine to knock ..setting off the knock sensor and messing up timing..

 

What exactly is my next step..

spend 10 minutes and 128 bucks and replace o2 sensor first and see if that works

OR

spend 4 hrs and 160 bucks and replace knock sensor first to see if that works

 

thanks for all the advise that I hope is sure to follow

[nige]

unplug the o2 sensor from it's harness located near the passenger side firewall under the hood. If you aren't sure which harness to unplug, follow the wire coming from the sensor @ the exhaust pipe. If you driveablility improves without the sensor plugged in, chances are it is the sensor that is faulty. Be sure it is not just caused by faulty sensor wires by using a voltmeter to test for current and continuity. You can still repair the wires, but there really isn't anything you can do to fix the sensor itself. Some people have luck extending the life of the o2 sensor by roasting the tip with a propane torch to remove carbon.

 

If this doesn't remedy the situation, you will have to look elsewhere.

[k9sar]

if it's th2 O2 sensor, I'm surprised you don't read a code 33.

[bsskibum]

now When I replaced tranny.. I did have to remove the o2 sensor. It was solid black on it. I am heading out right now to see if that did it...

 

reseting the ecu codes to blank before I start it and unplug co2 I willr espond in a few minutes.

 

EDIT:

ok just unplugged the o2 sensor..and it ran great!! felt like I had a new truck. Put me back into the seat.

BUT i forgot to reset the ecu before I started it.

so I am reading the ecu stickie right now so I can head back out there.

since I unplugged the o2 sensor if it is bad the ecu should ONLY throw back a 33 and not a 34 anymore right?

we shall see back in a minute.

Edited May 18, 2009 by bsskibum

[bsskibum]

k..here it is..

The o2 sensor is disconnected(wire/plug)

The ecu is/was reset to ZERO (using the ecu guide)

Ran pathy to operating temp..

Ran alot alot better.. didnt spuuter at all

Tested ecu again when I parked...

Came up with a 34 still (knock sensor)

whats the deal-io ?

so cool of everyone looking to help

[94extreme]

check the wires to the knock sensor.. otherwise i bet that is it.. o2 will throw out it's own code or it won't throw anything out.. knock sensor threw one out so, it's either bad or the connection is loose or whatnot.

 

as to 02 and knock sensor codes being related.. i'm thinking you may be confusing r50 here.

[bsskibum]

I am a total newb to pathy land so probably not..." i'm thinking you may be confusing r50 here."

 

I am running out to check all the wires for knock sensor.. now with the help of casey I have a exact location to reach blindly into

will report back very soon

[nige]

you can run the truck for a short period of time with the o2 sensor unplugged, just don't go for too long or you may damage your catalytic converter.

 

the knock sensor is underneath the intake manifold between the two banks of cylinders. It is threaded into the block.

 

i would repair or replace your o2 sensor, reset your ecu and then drive for a bit and see if the engine light comes on again. I'm not sure if there is any room to get at the knock sensor to test it with a voltmeter to make sure it's hooked up without removing the intake manifold

Edited May 19, 2009 by nige

[bsskibum]

you can run the truck for a short period of time with the o2 sensor unplugged, just don't go for too long or you may damage your catalytic converter.

 

montana has no emmision's you have to pass..

I have a filler/straight pipe where your catalatic converter is..

with magna flow muffler it sounds like I will crush all that gets in the way.. and if I can get this damn problem fixed it will run like it too.. heheh

I will be back on it in the am...

[k9sar]

the relationship between the O2 and the knock sensor is simple.....

 

If a sensor goes bad (lots of different ones may cause this), the ECU gets misinformation and makes adjustments based on the information it thinks is correct. In many cases, this will screw with the way it's running ans could cause rough runnign which could be detected by the knock sensor. In these cases, there are typically other codes thrown, followed by the knock sensor. Fix what's thrown first, reset and run again. In many cases, the knock sensor isn't bad, just detecting issues caused from other failures.

 

But... sounds like you are on the path to solving this.

[bsskibum]

thanks for all the help so far...

ordered the o2 sensor.. dealer didnt have one or checker/or reilys/ or napa..

so I wait for 3-4 days from sacramento..(didnt want to pay the 30 bucks to overnight)

168.00 bucks..

I really think also that the knock is hitting because of another sensor.. o2 first then off to knock sensor..

Now the o2 sensor I have in there the whole tip is black..

is that carbon?

well thanks again.. when part gets here we will get back on this thread!!

[k9sar]

yes. carbon. self defeating situation. Carbon buildup is one thing that fouls the O2 sensor which causes the ECU to adjust the mixture etc which makes it run inefficient which produces more crap in the exhause to foul the O2 sensor.

 

fun, huh?

[bsskibum]

k so its carbon...

how would I remove such a nasty thing screwing up my fun to be had in that truck?

 

found this on another forum..

[updated:LAST EDITED ON 22-Oct-02 AT 00:27*AM (EST)]>Use electrical motor cleaner (found in auto stores). Spray

>some in a small container and soak the end of the sensor.

>Brush lightly.

First of all. It's not whether it can or can't be cleaned. Anything can be cleaned, if you go about it right. The question should be, first of all, whether cleaning it would do any good, and if so, whether it needs to be cleaned. Oxygen sensors are exposed to such extreme heat that the only thing that it can get (dirty) with is carbon. Extreme heat will turn any organic matter, such as gasoline or oil, into carbon. Well the bad thing about that, is that baked carbon is not soluble in any kind of solvent, and even if it was, the sensing unit within the o2 sensor module, is not exposed, and is not visible. It is covered by what is usually a louvered steel cylinder. Therefor if you're going to brush it, use a wire brush and brush it as hard as you want, because it isn't going to hurt the steel cover. But this is the problem. The only thing that you can really clean with any success is the outer cover. Since solvents won't do any good, I really would not recomend using electric motor cleaner, since the active indredient in it is Trichloroethylene which is not a very strong solvent. not only is it's strength very low, but also, since it is designed to clean electronic components, it evaporates very rapidly, resulting in a very short working time.

Since o2 sensors are disigned to hande such extreme temeratures. The best method of cleaning them, is to heat the bottom part of the sensor (the part that inserts into the exaust) with a propane torch, to the point that it just begins to turn red. You do not want it to glow chery red, even though they are designed to take extreme heat, you can still over do it. Once you have it heated to the point that is just turns red, or to the point just befor it turns red, quench it in water. This will break free any carbon build up inside the sensor. After the first time, some pieces may still be to big to come out of the sensor so I would recomend doing it 2 to 3 times, blowing it out with an air compressor between each time. But I would have to say, good luck, since O2 sensors very seldom fail do to being dirty. This is not common at all.

 

Is it worth trying or just say screw it.. and wait for the new one to get here?

Edited May 19, 2009 by bsskibum