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Discussion Starter #1 (Edited)
LT1 cam tune datalog advice please (DM UNI file up)

I would like some help interpreting my first official datalog. I have read MANY threads on this forum and others and I wouldn't say i'm a novice anymore, but I may be only a step above. Regardless, I have included a link to the uni file. I have also attached a txt file that highlights areas that I have pulled out, that looked like key points of interest that I could use to better adjust the tune with (I'm pretty proud of it, took me 6 hours, I'm really starting to appreciate this whole tuning thing).

The log is in Park and only 9 minutes long, but that's because quite a bit of white smoke 'poofed' out of my engine bay a little over half-way through and I couldn't tell exactly what it was, because it was dark outside, but the engine didn't seem to mind, all the readings seemed good, and it leveled out, no leaks, or noticeable hiccups... I had just refilled the coolant and didn't bleed it after the thermostat opened. So I proceeded to get a somewhat full variable log out of the endeavor.

I'll sit down later and try to figure out what I think needs adjusted, after I get some sleep, but I figured I could post my rundown here and maybe have some advice when I go over the log and re-tune.

The tune is based off of several bin files I have acquired and tried to make sense of. Most of them are for a LT4 HotCam in a 94 Z28 A4. My setup is actually a custom grind cam with the same duration, just a 110 LSA. It is in a 97 LT1 Z28 with 561 heads & PAC 1218s, 1.5rrs on intake, 1.6rrs on exhaust, headers, and bolt-ons; Run by a 94 PCM, & 95 tune.

I had just installed a new IAC and did the reset procedure before the log, and I think it causes some problems, and in the end seems to come down where it should be at idle.
I've got some knock, some looks false, some looks true. I just have the 95 LT1 knock module and sensor, because i found the LT4 module virtually unobtainable.
It idles good in the beginning, then goes Closed Loop and won't idle, then dies, runs with 10% TPS, then I get on it, it starts retarding some, u know the bit.

My banks are split left-rich/right-lean most of the time, with a DTC 45. So I guess I need to straighten out my fueling, given that the o2s are telling the truth.

Any and all feedback is very appreciated. Thanks for reading, I tried to be informative.

DataMater UNI file ----- FileSwap.com : datalog3.uni download free
 

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Tried a couple of different execs both had failures unzipping, file corrupted and missing files errors...

FYI... BLM cells are selected by the PCM based on TPS/speed/MAP, cells 0-15 are selected by TPS not 0 and speed not 0 and RPM and MAP. Cell 16 = TPS=0 and speed = 0. Cell 17 TPS =0, and Speed not =0 and MAP very low (decelerating). Cell 18 = TPS not =0 and speed = 0. Bottom line 0-15 are for driving conditions, 16 for idle, 17 for deceleration and 18 for throttle while standing still. any fueling in 17 and 18 should be ignored as abnormal operation conditions.
Can you download Datamaster EE (free for 20 logs), the data is much better and easier to interpret..
If you can't post up the .csv e-mail it to me a [email protected] and I'll post it up for others to view.
Stalling in closed loop indicates an O2 problem, .csv should display O2 voltages to prove that.
 

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Discussion Starter #3
Thank you for your reply bobdec. I forgot that BLM cells 16-18 were for idle Park and decel, it was late :). I re-zipped the files using WinZip this time and uploaded to the first post.
 

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Shrike, Just realized your a '97.. I should be talking trims and grams instead of BLM's, no problem also it limits you log capability, what SW are you using. The .csv does not have enough data.. log shows you go south when hitting closed loop. You O2 fueling correction is seeing something drastic. However the ST blm's are not enough data. The ST's are the actual burn result and they are showing left pulling 10% fuel and right adding 10% fuel. That is AFTER PCM correction, the LT blm's (not listed) will show what the O2's were seeing prior to PCM correction. Plus the O2 voltages will show what's happening prior to going into closed loop and after. IAC and AFGS will show how much air is moving and where it's coming from, IAT will verify coolant temp to PCM is correct. Desired RPM will show up any IAC/vac leak problems compared to actual RPM. The more data on a log the better to isolate the problem..
Knock at idle indicates something really lean, or a mechanical problem, can you hear anything, showed up when you goosed the throttle..
What TB are you running stock or aftermarket, if aftermarket what brand and size, MAF looks stock, is it descreened ?, any bottom end work ?
Have plug wires been double checked, I've seen a non firing plug (burnt wire) or crossed wires (6 & 8) cause crazy fueling, split blm's .. O2's read raw fuel as lean and then PCM adds more, messes up both banks, non firing bank reads lean, PCM adds fuel and other bank starts to read rich, then PCM tries to correct it and things get confusing.... Just guessing here..
 

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My question is, if your using datamaster anyway, why don't you take full advantage of it's features and post up the actual data file that can be run on DataMaster. That way members viewing file can see the actual real time data.

To post the DataMaster uni file, you need to join a file sharing site and add file to the site and link it to ls1.lt1 in your post.
 

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Discussion Starter #6 (Edited)
Coco - I didn't post a uni file because I am not registered to a file sharing site, but I will work on that and try to get it up. Thanks.

Bob - The car is a 97, but with a 95 brain, so you're good. Sorry about the lack of data, I was trying to meet upload file size demand. I included more parameter data in the txt file. I will get LT BLMs and more data up. Thank you for explaining the fuel readings, that makes interpreting each part much more informative.

The discrepancy at idle has been there since I fired the engine after it was put back together, and has reduced frequency and moved around at throttle levels through 5 different tunes. It is loud popping out of the exhaust, can't tell which bank. It has always happened at around 1400RPM. I don't believe I have vacuum or exhaust leaks, I have triple checked with starting fluid, inspection, and listening. It's possible the exhaust valves are caked with some carbon, because when I was using compressed air @ 20 psi to hold valves up while changing springs, a little air constantly leaked out the exhaust port and crankcase... I've been trying to clean them with misting water and running SeaFoam through. Also, I have adjusted valves a few times by setting different lifter preloads and always yielded no difference.

The engine is stock except for emissions deleted, accessories deleted, cold air intake, headers, and the cam with valve springs and rods. 90k miles. TB is stock 48mm, clean. MAF is not modified, screened, and cleaned. Plugs and wires are new, but have not been checked for individual spark, although i check each wire after every run, because i am paranoid about the headers burning them, but the wires are wrapped and tied away from the heat. Wire placement has been triple checked and I have had it run at night to look for external spark.

I'm using TunerPro RT 5 to edit bins, CATS WinFlash to flash, and DataMaster EE to log.
 

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I don't believe I have vacuum or exhaust leaks, I have triple checked with starting fluid, inspection, and listening. It's possible the exhaust valves are caked with some carbon, because when I was using compressed air @ 20 psi to hold valves up while changing springs, a little air constantly leaked out the exhaust port and crankcase..
Could be a bent valve/not seating properly if you are losing air through the exhaust. I'd check again with compressed air to eliminate a valve problem first.


Mitch
 

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Discussion Starter #9 (Edited)
Damnit!!! Add another 6/8 plug wire swapped to the records. What a stupid move! and it's so easy to do. I have checked those plug wires over and over, knowing that it is a common mistake and sure enough! It got the best of me too. To help others - This is an easy way that I used to discover my wires were swapped: I just ran the engine for 10 seconds and found my cold header pipes of the 6 & 8 cylinder that weren't igniting and so weren't heating up. What an absolute C^#*! So much time and despair :)

Thank you so much Bob, for giving me your thoughts and making me think to check those damn wires again.

Here is the log with the spark going to the correct cylinders:
http://www.fileswap.com/dl/R1D6nF3Agf/
 
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