Some AutoXray scan results (pic test)

[Paul Workman]

I'm Not making a point, except to illustrate one of the "real time" files I captured with my scanner, newly upgraded to work with my "new" Z. (The data was imported into an Excel file for futher manipulation at some point.)

But, for the curious, it is easy to see how much dynamic info is possible to collect on a second by second basis and much more too (several options). Bottom line...It makes shorting pins on the ALDL connector seem VERY crude. This scanner has helped me on several occations pinpoint problems in just a few minutes. (Even though this was as much of a test of the upgraded software for the EZ Link 1000, this test data raises some questions I may have questions on.:confused: e.g. O2 Cross Counts...What is that, and what does it mean when the left/right sides not ballanced???)

http://i185.photobucket.com/albums/x220/6PPC_bucket/AutoXrayscantest.jpg

FWIW,

P.

[bradslt5]

the cross counts are when it goes from low to high dont quote me but i believe the number is 400-450 . from what i have been told the cross counts help you to tell if the o2 sensors are getting lazy . when the cross counts get slow the o2 sensors need replacing.. you might ck to see if the cross counts on the side thats 117 is slower than the other side you might consider replacing that o2 sensor . what model auto xray do you have i wonder if my 4000 can download to my lapptop

[Paul Workman]

the cross counts are when it goes from low to high dont quote me but i believe the number is 400-450 . from what i have been told the cross counts help you to tell if the o2 sensors are getting lazy . when the cross counts get slow the o2 sensors need replacing.. you might ck to see if the cross counts on the side thats 117 is slower than the other side you might consider replacing that o2 sensor . what model auto xray do you have i wonder if my 4000 can download to my lapptop

Cross counts...Good to know, and thanks. Looks like I might have a "lazy" O2, huh? (I guess that makes our (yours and my) points: The scanner beats the hell out of a paperclip and standing on your head, huh? :mrgreen:)

My scanner was being discontinued when I bought it 5 years ago, tho they still support it (which makes me a happy camper!:wink:) Mine is the EZ Link 1000, and the EZ-PC 500 USB software (USB cable provided) does import scanner data to my computer (obviously). I'm not familiar with the your particular unit, however, but I would think it would be possible.

If you have a laptop, it might be worth looking into some of the s/w available that would allow you to link your computer directly to the Vette's computer. I would have gone that route, except I didn't have a laptop at the time I bought the Link scanner. That said, tho the scanner is passive (it won't modify air/fuel tables, for example), it has paid for itself many times over...in lack of frustrtion if nothing else!;)

P.

[WB9MCW]

good post nice info from that tool.

[XfireZ51]

Cross counts deal with the AFR swinging between lean and rich. The AFR actually oscillates and that is done because of the catalytic converter. If you look at the calibrations in our cars you'll see that the rich voltage is actually lower than the lean voltage. This is done to force the oscillation in AFR. If it oscillates too quickly you'll sense a surge in the motor. Looks like the Right O2 sensor is a bit lazy. BTW, you have quite a bit of canister purge going on there.

[Paul Workman]

BTW, you have quite a bit of canister purge going on there.
Now that you mention it, it does seem to be so. :thumbsup: However, a later (near WOT) base run started out at that 99.4% initially, and then dropped to zero followed by a few fluctuations below 10% before remaining at zero (after the WOT period). Hmmmm... sez me. A sticking valve perhaps?:???: (How could that be after sitting almost 10 years???:rolleyes:)

This is from Wikipedia re O2 sensor design and operation - an interesting read.

P.

Operation of the probe


[edit (http://en.wikipedia.org/w/index.php?title=Oxygen_sensor&action=edit&section=5)] Zirconia sensor

The zirconium dioxide (http://en.wikipedia.org/wiki/Zirconium_dioxide), or zirconia, lambda sensor is based on a solid-state electrochemical fuel cell (http://en.wikipedia.org/wiki/Fuel_cell) called the Nernst cell (http://en.wikipedia.org/w/index.php?title=Nernst_cell&action=edit). Its two electrodes provide an output voltage corresponding to the quantity of oxygen in the exhaust relative to that in the atmosphere. An output voltage of 0.2 V (200 mV) DC represents a lean mixture. That is one where the amount of oxygen entering the cylinder is sufficient to fully oxidize the carbon monoxide (http://en.wikipedia.org/wiki/Carbon_monoxide) (CO), produced in burning the air and fuel, into carbon dioxide (http://en.wikipedia.org/wiki/Carbon_dioxide) (CO2). A reading of 0.8 V (800 mV) DC represents a rich mixture, one which is high in unburned fuel and low in remaining oxygen. The ideal point is 0.45 V (450 mV) DC; this is where the quantities of air and fuel are in the optimum ratio, called the stoichiometric point, and the exhaust output will mainly consist of fully oxidized CO2.
The voltage produced by the sensor is so nonlinear with respect to oxygen concentration that it is impractical for the electronic control unit (ECU) to measure intermediate values - it merely registers "lean" or "rich", and adjusts the fuel/air mixture to keep the output of the sensor alternating equally between these two values.
This type of sensor is called 'narrow band', referring to the narrow range of fuel/air ratios to which the sensor responds. The main disadvantage of narrow band sensors is their slow response: the control unit determines the exhaust gas composition by averaging the high and low swings in the sensor's output, and this process creates an inevitable delay (this statement may be misleading - see discussion).

[edit (http://en.wikipedia.org/w/index.php?title=Oxygen_sensor&action=edit&section=6)] Wideband zirconia sensor

A variation on the zirconia sensor, called the 'wideband' sensor, was introduced by Robert Bosch in 1994 (http://en.wikipedia.org/wiki/1994) but is (as of 2006 (http://en.wikipedia.org/wiki/2006)) used in only a few vehicles. It is based on a planar zirconia element, but also incorporates an electrochemical gas pump. An electronic circuit containing a feedback (http://en.wikipedia.org/wiki/Feedback) loop controls the gas pump current to keep the output of the electrochemical cell constant, so that the pump current directly indicates the oxygen content of the exhaust gas. This sensor eliminates the averaging delay inherent in narrow band sensors, allowing the control unit to adjust the fuel delivery and ignition timing of the engine much more rapidly. In the automotive industry this sensor is also called a UEGO (for Universal Exhaust Gas Oxygen) sensor. UEGO sensors are also commonly used in aftermarket dyno tuning and high performance driver A/F display equipment. Wideband zirconia sensor is used for Stratified Fuel Injection systems and for the first time can be used for diesel engines as essential ECU's feedback sensor for oxygen content in exhaust gas in the next EURO and ULEV emission stages.

[edit (http://en.wikipedia.org/w/index.php?title=Oxygen_sensor&action=edit&section=7)] Titania sensor

A less common type of narrow band lambda sensor has a ceramic element made of titanium dioxide (http://en.wikipedia.org/wiki/Titanium_dioxide) (titania). This type does not generate its own voltage, but changes its electrical resistance (http://en.wikipedia.org/wiki/Electrical_resistance) in response to the oxygen concentration. Its value varies from about 20 kilohm for a lean mixture to about one kilohm for a rich mixture. The control unit feeds the sensor with a low-current five volt supply and measures the resulting voltage across the sensor. Like the zirconia sensor, this type is so nonlinear that in practice it is used simply as a binary "rich or lean" indicator. Titania sensors are more expensive than zirconia sensors, but they also respond faster. In automotive applications the Titania sensor, unlike the zirconia sensor does not require a reference sample of atmospheric air to operate properly. This makes the sensor assembly easier body easier to design against water contamination. While most automotive sensors are submersible, zirconia-based sensors require a very small supply of reference air from the atmosphere. In theory, the sensor wire harness and connector are sealed. Air that leaches through the wire harness to the sensor is assumed to come from an open point in the harness - usually the ECU which is housed in an enclosed space like the trunk or vehicle interior.

[XfireZ51]

Paul,

CCP at WOT would be a problem IMO. Difficult to control fueling when the CCP comes in and enrichens the mixture or dilutes it by introducing air. I would expect CCP to take place at startup and idle. I have a few scans of my car and I'll take a look to see what mine is doing.

[bradslt5]

please enlighten me to the effects of the canister purge?this is new to me i have learned some stuff and am a dodo on other stuff . could this be bypassed ?

[Aurora40]

Paul,

CCP at WOT would be a problem IMO. Difficult to control fueling when the CCP comes in and enrichens the mixture or dilutes it by introducing air. I would expect CCP to take place at startup and idle. I have a few scans of my car and I'll take a look to see what mine is doing.
I'm pretty sure the manual describes when it happens, and I thought it was after the car was warm and at sort of a cruising rpm? I suspect if it purged at 0% throttle/idle, it would cause some lack of smoothness. But I dunno... I do recall reading about it though, so it's in there somewhere.

FWIW, I have an AutoXray EZ-Scan 6000. Mostly I find a laptop more useful for datalogging things like knock retard on a run, but the hand-held tool is useful for troubleshooting and is way more convenient to take with you. Plus it works on just about every car.

[tpepmeie]

Looking at a BMCB calibration (93-95), purge can be active if...

Coolant > 65C
MPH > 10
TPS > 3.5
BLM > 100

Then, once purge is active, the duty cycle of the solenoid is increased/decreased as the Integrator moves outside set boundaries (100-118). There are many other parameters involved, but this is the jist of it.

Todd

[Paul Workman]

Paul,

CCP at WOT would be a problem IMO. Difficult to control fueling when the CCP comes in and enrichens the mixture or dilutes it by introducing air. I would expect CCP to take place at startup and idle. I have a few scans of my car and I'll take a look to see what mine is doing.

Nice catch. :thumbsup: But, I didn't say that right.:o What I meant was in the course of a WOT run, the CCP started out at 99.4, but even before the WOT period, it had dropped. After the WOT period it remained under 10%...is what I should have said. I agree, 99% CCP at accelleration would be a problem. I'm going to keep an eye on the CCP for a while (keep the scanner plugged in and handy, should anything crop up....Another nice feature of the scanners, I recon!;)

P.

[XfireZ51]

Paul,

Just for grins I went and looked at one of my previous scans. I had 99% DC on the CCP as well. Knock Retard seemed to appear at about the same time. There should be a parameter in the cal to shut off CCP. Maybe Todd Pepmeier would know of it. Otherwise, I may try unplugging CCP solenoid and see what happens.

[bradslt5]

stupid ? time. so the vapors from the canister get introduced into the intake tract.? what would happen if this was dissconnected?would the computor start acting up if there was no airflow from this devise?

[XfireZ51]

stupid ? time. so the vapors from the canister get introduced into the intake tract.? what would happen if this was dissconnected?would the computor start acting up if there was no airflow from this devise?

when you're tuning part throttle, you really should disable modifiers like CCP and EGR. That gives a clearer picturer of the true BLM resulting from the VE and SA tables. With these other items operating, it muddies up the water. I've done that for some time now with no issues apparent. I was asking if the calibration has a "switch" setting that disables the CCP. Otherwise just pluggin it up works as well. Doing so may change the BLMs in the areas where CCP would normally discharge. The trick is first to get the base VE table right then bring in the modifiers and fine tune those specific areas.

[bradslt5]

wow so you do your own tuning / ? id sure like to learn how to due that . i used to tune allmy old drag cars but i am knew to this computor stuff. are their any classes that one might take to learn how to tune with a computor ?

[XfireZ51]

wow so you do your own tuning / ? id sure like to learn how to due that . i used to tune allmy old drag cars but i am knew to this computor stuff. are their any classes that one might take to learn how to tune with a computor ?

The answer is no. This is the closest I have found to being tutored in tuning an ECM controlled vehicle.
http://www.thirdgen.org/techboard/diy-prom/288763-prom-tuning-guide-book.html
Overall, some incredibly intelligent people on 3rd Gen.
I've been doing it for about 6 years. Keep learning more all the time but once you understand the basics, you find many similarities between different cars. The basic principles are the same like VE and SA and SD or MAF.

[WB9MCW]

Well you seem pretty good at it X fire did you used to own a crossfire vette?

My first vette was an 84 b4 the Z. I sold the 84 to a good nearby friend. It actually has less miles on it than my Z.

Do you know ZR-1 Pete of Des Plaines? He is a good friend of mine too and likes to tune and mod ZR-1's?

If not u should hook up with him. He is a wealth of ZR-1 knowledge. Maybe you met him at the Byron track day?

Do you live in the north, west or south of Chicagoland?

[XfireZ51]

Well you seem pretty good at it X fire did you used to own a crossfire vette?

My first vette was an 84 b4 the Z. I sold the 84 to a good nearby friend. It actually has less miles on it than my Z.

Do you know ZR-1 Pete of Des Plaines? He is a good friend of mine too and likes to tune and mod ZR-1's?

If not u should hook up with him. He is a wealth of ZR-1 knowledge. Maybe you met him at the Byron track day?

Do you live in the north, west or south of Chicagoland?


Thanks and yes my other Vette was a Z51 Xfire. Pete and Al were 2 big reasons why I bought a ZR-1 and not a C5 Z06. Also Bob Banks. I like to think that Pete and Al are very good at the mechanicals of the ZR. I think I bring the tuning ability to the table. Unfortunately, the definition files for the ZR are not anywhere near as defined as the ones of other motors. The TBI truck motor $42 def is thoroughly hacked for instance. As tpepmeir has stated, there are 600+ parameters for the ZR-1. You don't need all of them but you'd like quite a bit more than what's readily available today thru either Tunercat or Tunerpro.
Maybe the registry should work to fund getting these definition files more thoroughly hacked and then make them public domain. ;)
I'm in Bartlett along with =Jeff=.

[WB9MCW]

Yep, I figured that you may have known Pete already!

Pete and I go back over 15 years as friends. I used bench race talk with Pete at a Gyros joint in Wheeling years ago. Jorge and Nondos (vette owner) owned the place. Back in the day Pete had a hot Camero with a tad of rust but very fast (aka-sleeper) and I drove a 89 SC T-Bird (still do my DD now is a 97 Bird-V8 not SC though) and naturally we both wished we had a vette like Nondos.

Years passed and Pete and I lost touch (I started doing lunch hour workouts & salad lunch at a health club) and the Gyros place was sold. In 2003 when I scored my ZR-1 Pete could hardly believe it was me on the ZR-1 Net and sent me a PM and we hooked up again and keep in touch via the forum and emails and a few face to face visits.

We really have a pretty close knit group of Chicagoland ZR-1 Vette owners no doubt.

[tpepmeie]

Maybe the registry should work to fund getting these definition files more thoroughly hacked and then make them public domain.

I have completely disassembled and identified all of the LT5 calibrations. At one time, long ago, I public domained the entire BFXB calibration file. At the time, it had some minor inaccuracies which I corrected over time (with a little help from my friends....). Eventually, I pulled it down from the site.

There was absolutely no interest in it at the time. I'm not sure it got one response when it was posted. I think 99% of the guys out there would rather buy an off-the-shelf chip from Marc Haibeck (very good), or are satisfied with Tuner Cat. Which is all fine. It seems to me, even on Thirdgen, that the real technical innovation and interest is waning on the P4 ECM. Most of the effort has gone into OBD-II, and become "for profit".

My $0.02.

Todd

[bradslt5]

is there a way one can get ahold of a copy of that file.?

[QB93Z]

Todd, I am interested in learning more about the LT5 calibration file. Would you be willing to post it on the Registry again? Or is it possible to get a copy from you?

Thanks, Jim

[XfireZ51]

Todd, I am interested in learning more about the LT5 calibration file. Would you be willing to post it on the Registry again? Or is it possible to get a copy from you?

Thanks, Jim

Jim,

There are several depending on th year ZR you have. The Mask IDs for them are:

$8E 90 ECM 8331
$AF 91 8331
$D0 92 3993 or 3860
$F0 93-95 3993 or 6394

The def file will match the ECM you are using. There's one other little twist. GM made some slight mods on these def files during production. So, for instance, the $def file for my chip is actually a $D0A. It has 3 extra lines of code starting in the 7xx address area. Before that it matches what's on the $D0 def file. After that, the values are off.
Sorry if I'm muddying up the water, but its not as simple as getting the ZR-1 def file. :frown:

[tpepmeie]

Just to be clear I did not post definition files, nor have any available. I have not used TunerCat for years.

What I have posted is a text disassembly of the calibration section of the code. That could be made into a definition file, if someone has infinite patience. I use TunerPro software to modify calibration files, and have made the relevant definitions in the form needed for that software. They aren't public domain. Only 1 other ZR-1'er was given my TunerPro definitions, and he has been extraordinarily helpful over the years.

Dom, those extra three bytes were in all of the revised service calibrations published after about 1993. They affect startup fueling, and are of no real consequence once the engine is warmed up.

Todd

[XfireZ51]

Just to be clear I did not post definition files, nor have any available. I have not used TunerCat for years.

What I have posted is a text disassembly of the calibration section of the code. That could be made into a definition file, if someone has infinite patience. I use TunerPro software to modify calibration files, and have made the relevant definitions in the form needed for that software. They aren't public domain. Only 1 other ZR-1'er was given my TunerPro definitions, and he has been extraordinarily helpful over the years.

Dom, those extra three bytes were in all of the revised service calibrations published after about 1993. They affect startup fueling, and are of no real consequence once the engine is warmed up.

Todd

Todd,

Could you point me to that disassembly since its already been posted?
As for the extra 3 bytes, they still throw off the values when viewing a $D0A bin while using a $D0 mask in TC or TP. And there's some interesting stuff to look at after that address. Any chance you posted the .ads as well?
BTW, you've been very helpful yourself. :thumbsup: