OK whats going on in this log?

[Ho0ked]

Ok these are 2 logs 3rd gear WOT runs as close to red line as my road allows .

1st log

8/26/05-11:20:08 - Obd2
RPM Timing O2 1 Bank 1

3048 23 0
3184 22 0.02
3336 21 0
3484 20 0.02
3664 19 0.02
3968 18 0.02
4160 13 0.04
4348 12 0.06
4584 10 0.08
4792 9 0.08
5044 9 0.1
5252 9 0.1
5484 10 0.1
5680 11 0.1
5904 14 0.1
6104 14 0.1
6292 15 0.1
6464 16 0.1
6632 18 0.1
6784 19 0.1
6916 18 0.1
7056 19 0.10
7176 20 0.12
7312 19 0.12
7228 20 0.12
5264 39 0
5408 15 0.1
5348 13 0
5324 35 0
5280 35 0
5168 26 0
5072 24 0
4960 24 0
4848 24 0
4744 24 0
4636 24 0
4516 24 0
4420 24 0

---------------------------------------------------

2nd log


8/26/05-11:16:19 - Obd2
RPM Timing O2 1 Bank 1

2928 24 0.02 0
3072 23 0.02 0
3212 22 0.02 0
3360 21 0.02 0
3528 19 0.02 0
3676 19 0 0
3856 16 0.04 0
4048 14 0.04 0
4260 11 0.06 0
4452 9 0.08 0
4676 9 0.08 0
4896 8 0.1 0
5076 9 0.1 0
5772 9 0.1 0
5484 10 0.1 0
5748 13 0.1 0
5896 15 0.1 0
6072 13 0.1 0
6240 15 0.1 0
6376 15 0.1 0
6528 17 0.1 0
6664 18 0.12 0
6808 17 0.12 0
6956 18 0.12 0
7044 19 0.12 0
7164 19 0.12 0
6688 20 0 0
5252 37 0.06 0
5360 18 0.1 0
5452 14 0.1 0
5516 14 0.1 0
5604 13 0.1 0
5644 15 0.1 0
5644 21 0.08 0
5540 35 0 0


Please help

Thankyou

 

[TotalEclipse112]

A little background first. The o2 sensor is a weird thing, it kind of works like a battery on the premise of dis-similar material. It samples the outside air content for oxygen(outside the exhaust pipe) and compairs that to the inside oxygen content(inside the exhaust pipe), and like a battery the dis-similar materials create voltage. In the case of the o2 sensor very low voltage. That is why on an unheated o2 sensor there are only 2 wires because it needs no applyed voltage(heated have 4, 2 for the heating element power and ground and 2 for the sensing process). The o2 sensor should be making even sweeps from about 0.2v to 0.9v. At 0.2 volts there is a lot of oxygen in the exahust stream, little dis-similar material to create voltage, when there is a high o2 content this indicates a lean condition. Usually about 8 lbs of air to 1 lbs of fuel. At 0.9v the oxygen content is low, more dis-similar which will create more voltage. This indicates a rich condition of about 15 or 16 lbs of air to 1 lbs of fuel. Now what the ecu is shooting for is about 0.7v which is stiochometric 14.7 lbs of air to 1 lbs of fuel, for complete, efficent, emmisions free combustion. But it usually never gets there so it just goes back and forth from rich to lean trying to get there. Now from what I see of your logs you have up to 0.12v, something is way off. Primaraly the face that the entrys leading up to the 0.12v are extremly low, 0.1 repeaditly. What is happening is the ecu is attempting to compensate for and extremly lean contition and over doing it. Which will finally bring me to my point (sorry if I confused you in any way), either your tuning set up is off(too lean), or you have a bad o2 sensor. Most likely you have an exhaust leak or the o2 sensor itself is bad. Tho only reason that I suspect an exhaust leak is the fact that the readings go from on extreme to the other 0.1v to 0.12v is not normal, and the fact that at WOT the ecu ignors the sensors and operates on open loop, which is a set of pre programmed parameters on wich to operate(plus its the easy and cheap souloutin to the problem and we all want our problems to be cheap easy fixes), even if you set up is wrong. Or the o2 sensor is taking in external air throwing off the readings. So I suggest this, start looking for exhaust leaks, if you don't find one change the sensor, and if that dosent work go back to your fuel delivery set up and see if you have it set too lean. Which I assume you can control since you do have a logger. Hope this helps in some way and I didn't make your head spin.

 

[spyderturbo007]

At 0.9v the oxygen content is low, more dis-similar which will create more voltage. This indicates a rich condition of about 15 or 16 lbs of air to 1 lbs of fuel.

Tuning with an O2 sensor is worthless, I have seen DSMLink logs with no knock, great timing advance an O2's of 0.84V.

Now what the ecu is shooting for is about 0.7v which is stiochometric 14.7 lbs of air to 1 lbs of fuel, for complete, efficent, emmisions free combustion.

Wrong! 0.50V is the stoichometric point.

Now from what I see of your logs you have up to 0.12v, something is way off. What is happening is the ecu is attempting to compensate for and extremly lean contition and over doing it.

No, No, No!! Damnit stop spreading misinformation.

The ECU does not use O2 voltage at WOT for anything. The only thing a bad O2 sensor will do is max out the FT's, trip a CEL and trash his/her gas mileage.

To the original poster:

Go get a new O2 sensor, as I said above it won't screw up your tune, but will trash your gas mileage. As far as the logs go, the first log looks like you left your foot off the gas and then got back on again

For the sake of this post I will only be dealing with the 2nd log. Go ahead and add 1 or 2% to 6k and 6.8k. I see that your timing is dropping about 1 degree in those areas. It could be that the ECU is dropping you into a lower timing map based on airflow, but I don't know without some airflow numbers. Just add a little and re log the car. Other than that, it looks really good. Normal timing drop as full boost hits, and a steady increase to around 20+ degrees.

 

[TotalEclipse112]

No At WOT the ecu dis regards all input from all sensors and operates on a set of prametes pre programmed in the PROM. Thats why people tune with the o2 sensor. Even though its not doing anything as far inputs to the ecm, it can still tell you wether your where STFT is at running on the parameters in the PROM. As for .5-.7v is concerned, at .5 or .7v is the stocicometric range. Jesus when the hell did this site get so dam militant.

 

[spyderturbo007]

No At WOT the ecu dis regards all input from all sensors and operates on a set of prametes pre programmed in the PROM.

Wrong again! How could the car run with no input from any sensor???? Hell, it wouldn't even know that it was at WOT without the TPS. At WOT the ECU cares about air mass. It calculates this from the mass airflow sensor, intake air temperature sensor, barometric pressure sensor, etc.

Thats why people tune with the o2 sensor.

If anyone is only using a narrowband O2 sensor to tune with they should be slapped. Narrowband O2's are worthless when it comes to tuning!

Even though its not doing anything as far inputs to the ecm, it can still tell you wether your where STFT is at running on the parameters in the PROM.

I have no idea what you said there, but the ECU does not use FT's during WOT operation, only cruise and idle.

As for .5-.7v is concerned, at .5 or .7v is the stocicometric range.

AFR of 14.7:1 corresponds to, provided the O2 sensor is functioning properly, 0.50V.

Jesus when the hell did this site get so dam militant

Probably when people started getting sick of seeing posts full of misinformation and looked like they were written by a 12yr old. Posts full of wrong information/advise give this community a bad image that no one wants.

 

[TotalEclipse112]

At WOT the ecu operates in open loop, using no inputs from any of the sensors except the TPS, to tell it that it is at WOT. At WOT the ecu uses set parameters programed into it to operate.

I have no idea what you said there, but the ECU does not use FT's during WOT operation, only cruise and idle.

All I was trying to say was that even though it is operating in open loop disregarding the inputs from the sensors, you can use this information to tell what kind of fuel is setting is being utilized during WOT. If you don't belive me why don't you take a 12 week course on engine management systems and drivability. Or better yet why don't you go to a dealership and ask a tech. But since I am a stupid 12 year old spreading misinformation and giving the "community" a bad image why would you bother. Jeeze why listen to someone that actually does this stuff for a living, when you obviously have your own ideas of how these systems work.

 

[spyderturbo007]

At WOT the ecu operates in open loop, using no inputs from any of the sensors except the TPS, to tell it that it is at WOT. At WOT the ecu uses set parameters programed into it to operate.

Ok, Mr. Know-it-all, then explain to me how the ECU calculates the proper duration to open the injectors only using the TPS.

Does it just guess on the mass of air entering the combustion chamber? I think not. I can't believe that you do this for a living and you think that the only thing the ECU uses to calculate fuel delivery at WOT is the TPS. WTF?

By your rational the ECU will inject the same amount of fuel when it 100 degrees out, as it does when it is 40 degrees out. Also, you are saying that when you add any mod that increases flow (turbo, exhaust, intake, etc) that the ECU still injects the same amount of fuel it did before the air mass increase. Where are you getting your information??

All I was trying to say was that even though it is operating in open loop disregarding the inputs from the sensors, you can use this information to tell what kind of fuel is setting is being utilized during WOT.

If I am understanding you correctly, you think that the ECU uses FT's and TPS to determine the correct amount of fuel to inject. You need to go back to your 12 week engine management course and pay more attention. The ECU does not use FT's at WOT, AT ALL! All it cares about is AIR MASS, which you can't get from the TPS or FT's.

 

[TotalEclipse112]

I am really getting sick of trying to explain this to someone that refuse to except that they are wrong and know more than some that does this professionally. But I am going to attempt it one last time and then after that all I am going to respond with is that you are right and I'm wrong, all hail the dsm king, immediately after I will call Ira Porsche Audi in Danvers Ma, and explain to the Porsche service manager that I am a complete moron and cannot accept a position as a Porsche tech in January, at which point I will go find a McJob and ask if you want Fry's with that for the rest of my life and never touch a car again. So it here one last time.

Ok, Mr. Know-it-all, then explain to me how the ECU calculates the proper duration to open the injectors only using the TPS.

Does it just guess on the mass of air entering the combustion chamber? I think not. I can't believe that you do this for a living and you think that the only thing the ECU uses to calculate fuel delivery at WOT is the TPS. ?

By your rational the ECU will inject the same amount of fuel when it 100 degrees out, as it does when it is 40 degrees out. Also, you are saying that when you add any mod that increases flow (turbo, exhaust, intake, etc) that the ECU still injects the same amount of fuel it did before the air mass increase. Where are you getting your information??

It still uses the intake air temperature sensor to determine which look up able to use, which I will explain to you.

If I am understanding you correctly, you think that the ECU uses FT's and TPS to determine the correct amount of fuel to inject. You need to go back to your 12 week engine management course and pay more attention. The ECU does not use FT's at WOT, AT ALL! All it cares about is AIR MASS, which you can't get from the TPS or FT's.

I never said it uses Fuel Trims all I said was it uses per-programed parametes, which I will explain to you the simplest way I know how, to determine operating parameters for the engine. Keep reading you might learn something here sparkey.

At wide open throttle the reference voltage signal from the throttle position sensor approaches zero voltage. When that happens the powertrain control module realizes that it is at wide open throttle. Once the point of wide open throttle is reached the powertrain control module, disregards all inputs from the engine sensors, its called open loop, open loop also occurs when the engine is cold or after prolonged idle. Anyways back to my point when open loop happens the powertrain control module operates on a set of parameters which have been pre-programmed into it. How does it do this you ask very simply much like a common calculator does math. On a calculator when you press 5+4 it immediately responds with 9, thats how open loop works. It disregards everything except air flow, since fuel cut is a function of air flow and all dsm'ers know what fuel cut is, but it no longer uses air flow to schedule fuel delivery, but simply when x voltage is reached from the Mass air flow meter to shut off the fuel. Thats why when you just put a bigger turbo with no mods you hit fuel cut faster because of the increased air flow. Back to my point that is a discussion for a later time. In open loop, all of the parameters of the engine have been programmed into the powertrain control module much like math is programmed into a claculator, fuel delivery, spark advance, and air flow at that set rpm point, since the mass air flow meter is now only used to determine the time of fuel cut. When the Powertrain control module sees x voltage from the crank angle sensor(which bu the way is a variable reluctance sensor) it determines the engine speed. Once it determines the engine speed the powertrain control module uses a look up table for the intake air temperature that was programed into it and then directs the injectors pulse width, and spark advance, for the per-programed air flow at that engine speed, and then executes them. Keep in mind these are not inputs to the powertrain control module, but a set parameter that it is simply basing off engine speed and carrying out. These parameters exist for every rpm point from 0 to redline, and every intake air temp from -40F to 130F that the engine operates at. And in open loop can use the look up table programed into it to carry out. Thats how the engine operats with out sensors.

Now to tune in open loop, which is wide open throttle, you have to intercept the signals that the powertrain control module is putting out. To intercept the signals someting like an AFC is usually wired into the output wiring of the powertrain control module, which sends the signal to the AFC, is modified and sent to the components such as the fuel injectors, to modify the pulse width, thus adding or removing fuel. And intercepting the input from the mass air flow meter and changing it to a lower voltage so the powertrain control module never sends the signal for fuel cut. This is how it is possible to tune with a narrow band o2 sensor. Granted it is not as accurate as an exhaust gas temperature sensor or a wide band o2 sensor, but those are expensive and many people are tuning on a dime here, not everyone is a rich boy spending mommy and daddy's money you know. By modifying the outputs from the powertrain control module you can use the stock o2 sensor(which is not being used by the powertrain control module because the car is in open loop) to see how the modifications that were made to the fuel curve are working. Generally on a scanner .89 volts is lean and .92 volts is rich, at wide open throttle. The only other way to tune around open loop is is to get an complete stand alone engine management unit which has no per set parameters, and is completely tunable to various set ups. But once again that is a discussion for another time.

Thats it thats how it works without seeing inputs from the sensors. It pretty simple if you use it all the time. After this I quit I'm not explaing it any more, if you still don't get it good, great, grand, I don't F'ing care. Go blow up your engine with your shade tree mechanic tuning skills. Then when your car is dead and in the shop you can say "hey is there such a thing as open loop?" and when they say yes won't you feel dumb.

 

[scottsee]

TotalEclipse112....cut and paste?

Replace your o2. log RPM, Timing, o2, Airflow. 3k-7k on 3rd gear pull.

 

[Ho0ked]

Thanks fro the responses guys

Sorry to start a battle

Yes i'm tuning on stock front O2......

Don't have cash for a wideband and standalone's etc......

My car seems to be running faily well now, including gas mileage,
thankyou guys

My only issue now is posted in Turbo forum........



Please drive through................

 

[TotalEclipse112]

Glad to respond.

Also sorry if your thread was hijacked in any way and turned into a battle ground.

TotalEclipse112....cut and paste?

Nope I typed the whole thing out myself.

 

[spyderturbo007]

At WOT the ecu operates in open loop, using no inputs from any of the sensors except the TPS, to tell it that it is at WOT.

It still uses the intake air temperature sensor to determine which look up able to use

Make up your mind.....either it uses sensors or it doesn't.

I'm done, but do some reading and you will see that your are severely mistaken.

 

[TotalEclipse112]

I am really getting sick of trying to explain this to someone that refuse to except that they are wrong and know more than some that does this professionally. But I am going to attempt it one last time and then after that all I am going to respond with is that you are right and I'm wrong, all hail the dsm king, immediately after I will call Ira Porsche Audi in Danvers Ma, and explain to the Porsche service manager that I am a complete moron and cannot accept a position as a Porsche tech in January, at which point I will go find a McJob and ask if you want Fry's with that for the rest of my life and never touch a car again. So it here one last time.

Done and done, Mickey D's here I come. If you still don't get it, I give up.

Also your playing mix and match with my posts, comparing a general discription, to a highly technical one. Thats like comparing apples to oranges.

 

[DSMJim]

In open loop operation the only sensor it ingores is the O2 sensor. It uses TPS, MAF, CAS/CAM, Knock, IAT etc... It does run from a pre-set map however the O2 sensor no longer has a say in what the fuel trim will be. The timing is pre-set based on air flow and fuel based on air flow and temperature (plus other small variables).

 

[steve]

There is too much wrong information here to even try and quote it all. TotalEclipse, You know things about other cars but you continue to spout nonsense about DSM's.

First. We don't run speed density so our ECU uses the MAF airflow counts and the engine RPMs all the time to calculate the basic injector activation duration (BIAD). It doesn't matter if we are running closed or open loop at this point. BIAD is the amount of fuel for a stoichiometric mixture and is modified based on the input from the other sensors. In open loop the fuel enrichment map is used to modify the BIAD calculation. In closed loop the fuel trims derived from O2 feedback are used to modify BIAD to correct for changes causing errors between the calculated mixture and what the O2 reports. The IAT, Barometric pressure, ECT, TPS and battery voltage corrections all are applied after the open vs closed loop decision.

Our TPS increases it's voltage output as it goes from closed to open. If the MAF is bad it's used for limp mode but normally it's used to sense changes in throttle position rather than absolute positions. The ECU want to know if we are accelerating or decelerating and if the throttle is open or closed.

Fuel cut like the injector pulse width cap are protection limits coded in to shut things down in the case of overboosting from a failed wastegate actuator.

The O2 sensor code in closed loop actually dithers the fuel around the BIAD value and watches the O2 sensor voltage. It changed dither directions at reading of 0.51v on the "lean" side and 0.61v on the "rich" side. This is what causes the O2 voltages to cycle back and forth in closed loop.


Now what was the original question?

Steve

 

[TotalEclipse112]

Perhaps I have too much knowlege of other cars, primarally 1g DSM's, and not enough about 2g DSM's so I will humbly bow to you(and I mean that with all seriousness no sarcasam in any way intended). But also thank you for saying that open loop does exist, perhaps now spyderturbo007 will stop calling me an idiot.

 

[spyderturbo007]

But also thank you for saying that open loop does exist, perhaps now spyderturbo007 will stop calling me an idiot.

Now that it has been reinforced that you are wrong, please show me where I said that open loop doesn't exist.

 

[TotalEclipse112]

Does it just guess on the mass of air entering the combustion chamber? I think not. I can't believe that you do this for a living and you think that the only thing the ECU uses to calculate fuel delivery at WOT is the TPS. ?

By your rational the ECU will inject the same amount of fuel when it 100 degrees out, as it does when it is 40 degrees out. Also, you are saying that when you add any mod that increases flow (turbo, exhaust, intake, etc) that the ECU still injects the same amount of fuel it did before the air mass increase. Where are you getting your information??

Any more questions? Now that you have changed your story to try and look good for someone else.

 

[spyderturbo007]

I'm done with you.....

You have already shown through this entire thread that you have no idea what is going on.

I then ask that you show me where I said that there was no such thing as open loop. You reply by quoting me telling you that the ECU uses sensors, other than the TPS, to calculate fuel delivery.

 

[steve]

Any more questions?

Are you taking meds for your condition?

I don't see anything spyderturbo posted that I have a problem with. I wish I could say that about what you posted.

Steve