1995 Buick Regal GS, and TunerPro RT

[avis]

this is what i am left with after finally getting my car to communicate with my laptop. as the left side shows, it encompasses only 9 seconds of information, and yet there is no real usable information.

sure, if you watch the tach you can see it will occasionally stop at a number that corresponds to what the vehicle's actual tach is saying. and then every temp indicator occasionally lands on a number that corresponds to a realistic temperature for that particular fluid. the fuel correct signal hovers around 130, and i'm thinking that i've read where this or BLM or something is supposed to be there - indicating a general rich or lean condition at the time.




i obtained an aldl-USB interface from aldlcable.com in the hopes that i could diagnose my GM 3800's wandering idle speed issue, maybe change the table that tells it what high idle speed to use with what coolant temperature (in my opinion it high-idles for too long), and it's the little things like this that made me want to begin datalogging and analyzing my vehicle on a computer.

another strange issue i have is with the transmission, a famous 4T60E. it has been replaced with an entire new unit after my third (free) follow-up visit to an excellent transmission serviceman and friend. it still exhibits an issue i noticed right after the first encounter with a transmission rebuild - TCC likes to shudder/slip and this slippage eventually exceeds a limit and locks out 4th gear and the TCC control. my transmission guy checked and replaced solenoids, went through the entire transmission twice, and replaced it entirely on the last run, all to no avail.

one big clue i had towards other issues was the fact that changing plugs & leads early on in my ownership of this car led to NO shudder in the TCC, and only subtle "surging" feelings of what i assume is slippage.


now i have read into and tried to correct this bouncing indication issue, and i had hope that one more recent post would hold the key. i put in a "pause before reset" command in the macros, i can screenshot this if necessary... but playing with the pause time (ms) didn't change a thing about how the data appeared to scatter across the screen.

so here i am, wanting to know what the IAC is doing, what the idle target speed is. maybe find out why it idles funny. just having information in general seems great, and now that i've verified at least the ALDL and the software function, i'm wondering what's next on the path to retrieving good, usable info. any help is greatly appreciated.

thanks in advance,
kyle

[avis]

well now i have to update. after messing with the definition edit a bit more i decided to use 25ms for the pause time, and i put it at the end of both macros (the second for additional information) and guess what? it works.

i can see everything that's going on and it is correctly working as a diagnostic tool. now i have to find out why the O2 sensor is basically cycling between minimum and maximum over and over. and how to prevent the TCC slip that is likely causing my TCC/OD override issues.

[turbodave]

well now i have to update. after messing with the definition edit a bit more i decided to use 25ms for the pause time, and i put it at the end of both macros (the second for additional information) and guess what? it works.

i can see everything that's going on and it is correctly working as a diagnostic tool. now i have to find out why the O2 sensor is basically cycling between minimum and maximum over and over. and how to prevent the TCC slip that is likely causing my TCC/OD override issues.

If the O2 sensor you're monitoring is a narrowband as I assume it is because the values are displayed in mv, then that's how narrowband sensor operate. When in closed loop they fluctuate wildly above and below the center value. The only time they'll be fairly stable near a value will be in open loop operation (cold motor, etc.)

[EagleMark]

Yup it's called cross counts. Some ECM will stop cross counts in PE or other open loop operation too.

[avis]

okay, i shouldn't have left that last post... uncovered the O2 sensor thing after very little reading. i have been studying the line-graph monitors very closely and i would like some experienced opinions on what is going on.

to clear up the transmission failure-mode issue, it is very obvious from the performance monitor that the TCC clutch is slipping far too much. the extended slipping in excess of a set limit is simply kicking on a TCC error and disabling both 4th gear and the TCC... so it's likely the piston bore oversizing and fluid bypass issue i've read about. looks like the only fix here is a new torque converter with a fresh piston assy.

as far as engine performance goes, this thing is way off. i'm posting pictures here since this is general car operational theory, and i haven't got any model-specific inquiries as of yet.

Cold Start & High Idle (Thumbnail due to excessive width)

NOTE: since i didn't have the knock count monitor visible, i figure it's worth mentioning that 12 knocks were counted during startup - six while cranking (maybe starter noise?), six with the flare.

you can see in the above image that the LV8 and RPM stabilize rather well in open loop, so i can't exactly account for why the timing wanders retarded and then quickly advances again. i've noticed this happens every time i start the vehicle with tunerpro logging - wether cold, semi-cold, or hot. i tried the latter a moment after first shutting down to confirm this gradual retardation. anyhow, after timing re-advances on the right side of this image, it stabilizes at a solid (though suspiciously high...) number that slowly falls with the high idle. nice and smooth until...




this next image depicts the sudden shift into highly inconsistent idle, and isn't it nice and coincidental with the transition into closed loop! can anyone wager a guess as to what this means? i notice the fuel correct is going crazy as well... is this an indicator of dirty injectors or something? what about the sudden spikes of retarded timing - is this a misfire?

at 3.5 minutes in, i start noticing anomalies with the O2 sensor readings. the otherwise smooth peaks now begin hiccuping, as shown below:



after the hiccup in the O2 sensor reading (and inverted timing spike), there is an abrupt and shaky 200RPM drop followed by an idle rise of roughly 100RPM. the fuel correct at this time goes from as low (rich?) as 100 to as high as 150. is this like BLM in that it needs to ideally be about 128?

you can see on the right side of that last image that the O2 sensor's cross count frequency increases. during loaded operation (driving the vehicle up at highway speed) this frequency increases even further, but will occasionally shift to a lower frequency for two cycles or less immediately following a drastic change in ignition timing.


more on this later when i have time, but: something tells me the timing is getting too much advance some way or another and causing this detonation. i've tried to spray out a vacuum leak but i find none, and all vac lines are flexible and soft. i will show you guys my typical acceleration from a dead stop. it is almost guaranteed the knock counter will register at least a half dozen, and half the time the knock retard value rises from zero. just sounds like a bunch more stuff to consider.

i am posting these pictures in an attempt to build some sort of knowledge base of datalogging interpretation, and hope to acquire some general information that might benefit anyone trying to diagnose a computer on wheels. i will post more later, but please; if these images aren't particularly welcome, just let me know and i'll stop posting them. who knows how long imageshack might keep them up anyhow.


thanks for any opinions, suggestions, assistance, etc.,
kyle

[EagleMark]

The 02 sensor readings do not seem strange or wrong, fueling is kinda following what it's told to do.

But those spike drops in timing do not seem right at all, then causing other readings to suffer.

Do those timing spike drops happen at same time as a knock count?

It's always good to know your fuel pressure at idle and when motor revved is not dropping... something I always need to know when working on a car with issues. But I don't think that's your issue, don't know your car well enough but something in timing is wrong, maybe a failing EST. They are known intermitent issue causers... HTH!

[blrmkr8609]

well now i have to update. after messing with the definition edit a bit more i decided to use 25ms for the pause time, and i put it at the end of both macros (the second for additional information) and guess what? it works.

i can see everything that's going on and it is correctly working as a diagnostic tool. now i have to find out why the O2 sensor is basically cycling between minimum and maximum over and over. and how to prevent the TCC slip that is likely causing my TCC/OD override issues.

I am going to be trying to connect to my 1995 Buick Regal tonight and was hoping that you could save me some time. What definition file did you start with and edit for your car?

I also have no TCC lockup and very intermittant stalling at idle. Thanks!

[EagleMark]

TunerPro Look Up Project in an Excel spreadsheet for all GM cars.

http://www.gearhead-efi.com/Fuel-Inject ... up-Project