When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Car is running rough, engine is shaking even at idle and im getting a gas smell which will probably be obvious for you experienced guys when looking at the data, and the DA connecting kept toggling green/red. Other than that this is my first log ever and am hopeful that someone will take a look and let me know what they think, whether it was a proper test log or if I should switch my files up or what not. Its hard to be certain which adx file will work for what is probably a mostly stock tune on the ecm.
This run is with the everything stock hooked up (minus t56 swap items), egr solenoid line to egr has been plugged (i had a engine stumble just off idle), and using existing chip/tune which was set somewhere around 2008 (pre t56 swap) via Wong's Performance Engineering in Vancouver, WA. I had my autoprom in passthrough mode with the Super_8dm2.ecm imported as the xdf file and 8D_90-91_Corvette.adx loaded (both from tunerpro website).
The first rpm spike was a rolling start then floored, with a quick shift into 2nd and floored for just a moment. 2nd rpm spike i think was simply first gear but held a little longer, then towards the end i did a 2-3k rpm hold for a few moments.
So yeah, i'm basically looking for feedback on proper logging methods and tips for what to keep my eye on while looking at the data.
Great thanks! Its a stock o2 sensor, havent converted yet. Wanted to get some data points and and identify issues before i started working on more conversions.
1.) You're spending the vast majority of the time in BLM cell 4 (the idle cell). Even when the car is not at idle speeds. Not sure what that's all about at this point.
2.) The BLMs are diving down to around 108-111 as soon as you get into closed loop, so the ECM is detecting a rich condition and attempting to compensate for it.
3.) Your coolant temperature doesn't get above 160F. What thermostat are you running?
4.) The ECM is also commanding a ~9.5:1 AFR when you go WOT. Granted we need to see what the actual AFR is with a WB, but that's freaking rich. My guess is the actual AFR is going to be way too rich as well.
Do you have the factory chip you can put in there? It's probably good to get a stock baseline to start with before evaluating "performance chips".
"You're spending the vast majority of the time in BLM cell 4 (the idle cell). Even when the car is not at idle speeds. Not sure what that's all about at this point."
"2.) The BLMs are diving down to around 108-111 as soon as you get into closed loop, so the ECM is detecting a rich condition and attempting to compensate for it."
i need to learn that acronym, dont know what it is
"3.) Your coolant temperature doesn't get above 160F. What thermostat are you running?"
Im guessing its a 170, i cant be sure since its been years since ive changed it
"4.) The ECM is also commanding a ~9.5:1 AFR when you go WOT. Granted we need to see what the actual AFR is with a WB, but that's freaking rich. My guess is the actual AFR is going to be way too rich as well."
Its always seemed to run too rich. I replaced all valve seals recently then I pulled the egr hose off to get rid of an off-idle stumble, ran great for a few days then started acting like its running on 7 cylinders. I definitely need to go back through the plug wires and such, hoping its not a failing injector
"Do you have the factory chip you can put in there? It's probably good to get a stock baseline to start with before evaluating "performance chips"."
ive never had a factory chip, bought the car with a jet chip then got it dyno'd it a few years later.
"Also, what cam are you running?"
The engine is a crate engine install prior to my ownership, the cam might be just a crate engine cam (i might be able to narrow it down to the exact crate engine when i get back to the house/paperwork). The engine appears all stock (intake,runners etc) except for the 1.6 gold roller rockers. I probably posted the crate engine ID here on the forums years back.
Im home and have some time to type! First, thanks for getting back so soon on that log file. BTW i ran across your website whlie researching tunerpro, very impressed with your car and what you've done with it. I have a #'s '70 rs that will eventually return to daily driver status, but it won't be near as clean as what you've done with yours.
Back on topic, heres whats in the '91:
Engine: part#12513151 ENG-5.7GW (gm goodwrench?) w/~80k miles
Heads: #14101083 w/ 1.6 crane gold roller rockers
Intake: TPI stock setup
Cam: ?
Headers: Edelbrock 6876; 1-5/8" Dual cat
the crate engine # on the reciept lists a different head # that what is on my car, so who knows if they didn't stop there and threw in a completely different cam. Below is what is listed with that engine:
1986 AND UP 2 BOLT MAIN 1 PIECE CRANKSHAFT SEAL BLOCK( NO MECHANICAL FUEL PUMP PROVISION)
NODULAR IRON CRANKSHAFT
POWDERED METAL CONNECTING RODS
FLAT TOP HYPEREUTECTIC PISTONS
9.6:1 COMPRESSION RATIO
HIGH VOLUME OIL PUMP
SHORT WINDAGE TRAY
SINGLE ROLLER TIMING CHAIN
Yeah, that's a very mild cam. No reason a factory AUJP chip wouldn't work on it. Assuming what you have is a Jet chip, more than likely it's mostly stock anyway. Though I will say that 9.6:1 compression seems awfully high for an iron headed engine (which I'm assuming it is). Not sure what the local octane rating is in your area, but we'd never get away with it here in Los Angeles with the lousy 91 octane we haev.
Any rate, the BLM reading below 128 (far below in your case) means that the ECM is detecting a overly rich condition and is pulling fuel out of the mixture.
Could be due to a number of things including (but not limited to)
fuel pressure too high and/or bad fuel pressure regulator
bad spark plug(s) or ignition wire(s)
bad ignition coil or distributor cap
leaking injector(s)
bad sensor(s)... although I wasn't getting an error code on any of them that would matter. Note that I did see an error on the vehicle speed sensor.
Any rate, you'll need to figure out the issue. One clue is that since the ECM is detecting it, all or at least part of the problem has to be on the same side of the engine as the O2 sensor. If it's a bad plug or wire, it would have to be on that side, since the ECM is "flying blind" on the other side without the O2 sensor.
Any rate, the data can't really tell us much more than that IMO...
Im assuming the VSS error is due to the Dakota Digital (sgi5?) unit that i put in. The ECM definitely isnt happy with it, but it would only throw an engine light when one of my connections gets loose (needle drops to 0, followed by CEL). But my speedo works normally otherwise, i set it by getting on the highway and adjusting till the odometer tripped 1 mile at the green mile signs consistently.
Engine-wise, everything you listed is new except the wires (i replaced the distributor due to bad pickup coil). I kicked the car over last night in the dark and didn't see any visible sparks coming from the plugs distributor etc. I think one of my wires might be damaged from touching the headers, thats next on my list to test.
"One clue is that since the ECM is detecting it, all or at least part of the problem has to be on the same side of the engine as the O2 sensor. If it's a bad plug or wire, it would have to be on that side, since the ECM is "flying blind" on the other side without the O2 sensor."
This struck me as brilliantly simple, wish i had thought of it first. Genius!
I looked up BLMs yesterday. If i understand this right, Block Learning Multipliers are used with INT(integrator) to make long and short term fuel adjustments (im guessing via injector pulse widths?) to keep the car running at an ideal air/fuel ratio using rpms plus manifold air pressure (for BLMs) or O2 sensor (for INT). Seems they set 128 as the target value, with a range of 105-150 (not sure on exact range in my ecm). BLMS are divided into cells each containing a range value, and within each of those BLM values is found yet another range of INT values. Am i on the right track? Talking technical is not my strong suit lol.
Anyways, as you said i need to get back to flushing out the issue. Its never ending with this car, or my other one, or that third and fourth one...
Ultm8z did you use a log analyzer for that file or use tunerpro? I finally got an analyzer setup, the steep learning curve continues while getting all this stuff working right. Im using 84elkys v11u, and its got alot of info to look over in there lol
Ultm8z, i did another run after finding a bad exhaust gasket (on the drivers side) and swapping in new engine mounts, take a look if you get a chance thanks.
I had no idea what was waiting for me when i tackled those mounts, hoodog!! I put oem ones back in, but later on down the road if i get new headers/exhaust i'll look at getting solid mounts so i won't have to worry about engine sag again (though the new ones didn't seem to lift the engine up any).
I might still have an exhaust leak, but i couldn't find one in the header itself which is what i have been assuming for a while now. After new gaskets i still have a noise but i think its downstream of the header, maybe even at one of the catalytic converters.
Looking at the data it seems my BLMs are finally out of cell 4 but im not sure what to do with this data yet. Im going to go back to the stickies and see what i can make of this, and also look at getting a wideband setup.
Note, on tunerpro i could see afr at the dial screen but couldn't see it on the graphs, the only option is requested afr which never varied from 14.7 iirc. Im sure im just simply missing it.
Your coolant temp seems to have been corrected. It's getting up to mid-190's now.
Still struggling with low BLM's though. Here's a screen shot of your BLM history. Note that you didn't hit a lot of the cells. I've also attached the SAUJP ADX file that I'm using to generate this history. Assuming you have no other malfunctions going on, then this is simply tuning related.
What I typically recommend is to drive around with the history view turned on so you can see all the cells you've hit or missed.
Unplug the ECM to reset everything. Then drive around for a while to get the relearn process well established. Then turn on the history view and start trying hit as many cells as you can. You can see the history table being updated in real time.
You can then use my EZ VE tool to (also attached here) to then dial in your VE table. People have reported to me that it only takes 1-3 iterations to get the table dialed in using (it took me two iterations).
The one thing that's off the wall is that your ECM is commanding mid-9's AFR. That's mind-bogglingly rich. Without a WB, it's impossible to say what your actual AFR is, but my guess is it's probably too rich as well. But if you want a dialed-in tune, you'll need to get the WB (and preferably hook it up to TunerproRT).
When tuning the VE, try to stay on the rich side of 128. What happens is that if you're BLM is on the lean side (>128) just prior to going into Power Enrich, the ECM will richen up the PE AFR proportionally to how far above 128 you were. That'll make your final commanded AFR richer than what you're programming in for it... i.e., you tell the ECM you want 12.5:1... but ECM sees you were at 134 BLM and decides to make it 12.5 x 134/128 = 12.0:1.
Go ahead and post your bin. I'm curious to see what Jet did with the PE AFR and why it's so programmed rich like that.
Edit... won't let me upload the adx file here. PM me your e-mail address.
Ive attached Toms tune that i pulled from the car, i no longer have that jet chip.
Note that Toms tune is only good when looking at test1 (used autprom just to datalog). The test3 log was with bin 52030_D and S_AUJPv5 xdf (edited only for the manual transmission scalar and flag) with the matching narrowband adl file 2030_D5-NBo2 (all three files from the zipped file). No parameters were copied over from Toms tune, so unless i somehow fumbled up the files somewhere (or not using autprom correctly) then the test3 log should be completely unrelated to the Tom tune and i suspect its showing that there is an issue present with the car.
Correct me if im not referencing the files for you correctly, im still getting used to this stuff
Well, the commanded AFR in test3 seems to match Tom's tune.
Here's a screenshot from my Tunerpro replay. Commanded AFR at ~4400 rpm circled in red.
Note that the commanded AFR based on the values in the bin work out to 9.83:1 at 4400 rpm. But it's rich everywhere. Unless the car was tuned on dyno and it took that kind of commanded AFR to get the actual AFR you'd want (roughly around 12.75:1), then these PE values are ridiculous IMO. It has to be belching black smoke out the tail pipe like crazy when you're WOT.
But even if that was the case that it was tuned on dyno with a WB O2 hooked up... if you had to command 9.83 to get 12.75 at the WB O2 sensor, it would indicate there's something wrong with the fueling system or the injector parameters or something else.
For comparison you can also see what GM did with the factory AUJP PE AFR's. They're too rich as well IMO...
Iirc tom said he set afrs somewhere in the 11s (lower than he liked but still ok in the realm of gm) to avoid detonation. He used a chassis dyno, and im pretty sure a wbo2.
Whats got me is how i can load what should be a completely different tune and still get similar results. Ill burn a chip to make sure i didnt somehow have the same tune in the autoprom and run it in passthrough mode for data only
ULTM8Z, what kind of NB o2 mv readings are you usually seeing in your own datalogs during WOT runs? Looking at Alan's datalog, it looks like he running bit lean (around 850 mV) during WOT? I would shoot little bit richer (higher) with NB o2 sensor readings, if WB isn't available.
I don't put a lot of stock in what a NB says, much less tune around it. After all, what does 850 mV correspond to? 12:1? 11:1? It's a meaningless reading in that regard.
really need to get a WB if you want to start knowing what WOT AFRs you're getting.
I don't put a lot of stock in what a NB says, much less tune around it. After all, what does 850 mV correspond to? 12:1? 11:1? It's a meaningless reading in that regard.
really need to get a WB if you want to start knowing what WOT AFRs you're getting.
I absolutely agree with you that WB is your best friend while tuning. I'm still curious to hear what kind of NB o2 readings you (or someone else) are getting during WOT? My NB (located in driver side collector) is showing constantly 880-900 mV during WOT while WB (passenger side collector) AFR is 12.5-12.8. It would be interesting to compare the readings with someone else.
LC2 showed up yesterday, that was alot faster than i expected through summit. When hooking this up, can i just pull out the nbo2 and swap in the wbo2? The wiring would have to be set up properly of course, but I would like to avoid the downtime of installing a new bung in the exhaust.
Basically you need to hook up the WB signal wire to pin F14 on the ECM connector. Then wire the power and ground wires per the instructions for the particular WB.
In TP, you have uncheck the box for Opt2 b7.
You also have to check the box for Opt1 b5 for the LC-1 WB (make sure all other WB option boxes are unchecked).
Raising this post back from the dead, ive updated the engine with new manifold gaskets, egr valve and plug wires and then i took the car to DEQ to see how bad it would fail, but it ended up passing with flying colors! Didn't expect it, but i'll take it lol. A new bung is in the exhaust for the wideband but i haven't wired that in yet to the ecm and will have to tackle that another time. Today was spent just trying to brush up on Tunerpro basics (ive forgotten alot!) and get some more data.
This is where i'm probably getting off on the wrong foot, i may be trying to use the wrong files now that its been 7 months and i've forgetten where i was at. I wanted to run Tunerpro as an emulator and datalog, so started off loading up the following files to the program:
ADX- S_AUJP_v5_2030_D_NBo2
XDF-Super_8dm2
BIN- 52030_D_t56_egr
The bin was a file i edited last year for manual transmission and edited egr values to try to disable its function. I now went back in to restore EGR function but after surfing the forums and google i couldn't find the original values. So i peaked at the original file and edited as follows and renamed the file to reflect egr function:
EGR Diagnostic Min. Vehicle Speed=0
EGR Enable Min MAT Temp=-40
EGR % TPS Disable Threshold=0
EGR % TPS Enable Threshold=99.61 <-This value caught me by surprise when i went back in after the datalog to record the value, i thought i entered something just off idle. Wouldn't guess the software would update this number but maybe the value i enter was converted once i saved it? I'm guessing this value should be somewhere 1-10% so that it is working between idle and full throttle.
So now I've got a 25 minute log and noticed a few favorable changes from last year, namely the AFR no longer drops to the 9's and the BLMs seem to be going back to 128 more often though it does drop down low during certain stretches. Also, i get a Check Engine Light value 23 "MAT Sensor Low", i'll have to open up the hood and see if i somehow disconnected the temp sensor. Hopefully I am finally getting somewhere with this!
After connecting the MAT sensor I adjusted the EGR TPS % Enable= 5% and burned a chip. Drove around watching the egr % duty cycle but never saw it read anything but 0.0%. I'm obviously off on how to set this guy. I'll attach the log since it has the MAT values.
Besides that, the car feels strong and is alot of fun. Maybe its just the exhaust note, but each time i get this thing rolling after a period of time im always impressed by how much it sets you back in the seat. Its not super quick by todays standards, best i've done is 14.1sec/99mph quarter mile and i probably haven't done anything to better that but its still alot of fun to drive.
Lastly, on this run, i haven't noticed this certain hot smell coming from the engine bay thats been typical for this car these last few years. Hope its gone for good, but im probably not that lucky.
Looked at your latest log.... Your BLM history table is showing BLM's all over the place.
I haven't re-read through the entire thread, but I did look at the engine combo you posted. Remind me again why you're not just running a factory AUJP bin on this engine?
I think i went with S_AUJP because i was under the impression it was the most current version of AUJP. Part of my problem with this process is knowing what applies best for my car, which is compounded by having a mystery crate engine and converting to a manual transmission plus dealing with faulty engine parts. You think it would be better to just use an AUJP bin?
SAUJP is kind of an improved version with features suited for tuners and a WB O2. functionally its "mostly" AUJP, but I'd still prefer to baseline you with a known quantity.
what's your current idle vacuum and at what rpm? if it's up around 19-20Hg, then it's likely very near a stock cam.
Looking at my last log, with the coolant temp at 207 degrees and MAT at 114 degrees, the car idles at ~700rpm and ~33kPA which converts to 9.7hg (inches of mercury=hg?)
Updates! Been a bit since my last post and a few things have occurred. New dual cats installed (old ones were blown out), the muffler had completely broken away from the exhaust where it arches over the axle and had a shop re-weld it (note, if you need to pass deq then a disconnected muffler turns out to be a good way to fool the tail-sniffers). Also newly installed are some fuel injectors and and adjustable fuel pressure regulator! After finally absorbing from the forums that the stock injectors are crap and then realizing how easy it is to test the injector ohms i then found two bad ones (12 ohms) and decided to install a rebuilt set from Southbay.
So below i go through how i set this up and would like to know what items i need to address that i didn't cover below. Eventually i want to end up using the saujpv5 bin so i can have all that utility.
The new injectors are 24lb 0-280-155-832. It didn't come with any kind of offset numbers, and Southbay didn't have numbers for me over the phone. They described them as ford EV6 (goes over my head what EV6 is), but what i found on the internet was a Stan Weiss table that lists them as a volvo injector:
As my luck typically goes, i couldn't find a darn thing on the 832 injector to use for offsets. The closest injector data i could find in a pinch was the 715, which may not be apples to apples but it appeared to be pretty close:
Using that, i found a thread on the thidgen forums that listed offsets, now i just need to know how to use them (properly if i can!).
So at this point i just threw stuff together and hoped it worked. I used the AXCN for 91 vette because i couldn't get the saujvp5 bin to work without going into limp mode. I didn't want to use the stock aujp because i didn't want to fight things with having the manual trans.
I plugged in FNPW_Offset into the bin, interpolating the values for the table:
and then zero'd out the low pulsewidth table which seems to be the general consensus on these forums with new style injectors:
After all of this, i set the prom and turned the engine over and watched the BLMS and then adjusted fuel pressure. I finally ended up at just over 50lb on the rails (45lb at idle and hose connected) and 21lb setting in the bin.
So i got all this done just to hit the road for the Rod Run to the End of the World in Ocean park, a 3 hour drive. Literally over the river and through the woods to my wife's grandmothers place lol. BLMs were rich to start but by the end of the drive it was sitting right at 128, seems to be good! Throttle response seems to be a little light, and total power seems to be low when getting on it so I'm pretty sure i need to tweak some more dials. So far I've only adjusted low pulse width and voltage offset and injector size.
Anywho, coffee cup is low and the morning is getting away from me so i need to close this out. Any tidbits on which tables/flags/scalars need to be adjusted at this point would be appreciated, thanks!
Realized i made an error on the 14.4v offset above, should be .6312 msec so i had to go back into the bin and adjust that. Then, since it seemed like my fuel pressure was ok where it was at I removed my fuel pressure gauge from the fuel rail and put the original schrader valve back in .
Afterwards i found that, for whatever reason, the inj size in the bin was at 23lb not 21lb (must not have saved). I decided to leave it as is and kick the car over and saw the BLMs were running away lean into the 140s (figure its due to the incorrect 14.4v inj offset). I bumped the inj size in the bin to 25lb and all seemed to settle in nicely. My only issue is the CEL would trigger for a high map sensor, seems to be connected right but I could have it going to the wrong nipple on the intake at the rear. Does it matter which one its attached to right there? Seems like both would be straight to manifold pressure. Maybe its something to do with the AXCN bin.
So now my wife says it doesn't stink of gas when following behind me in her car which is an absolute first. REALLY, REALLY happy about that and has been a long time coming (about 14 years)! Hope I'm just down to learning the fine details on Tunerpro to get this engine dialed in. It feels like it could use more punch at full throttle but that might be resolved as i go along (could be a slipping clutch, read below) and I still have that darn WBo2 to wire in!
For all that, i had a blast at the Rod Run seeing all the cars. Its a bucket list thing if any of you haven't seen it, the one in Ocean Park Washington. Plenty of old and new cars (and saw several third gens in the show). Tried to get in on the burn outs on the main drag but on my first try I roasted the clutch. Gah! lol still drives, but now the pedal action feels closer to the floor and needs replaced sooner than later. Oh well, I'll just keep on keepin on!
05-04-2018, 04:33 PM
