Here are two scans. I didn't remember to clear the knock learn for number 2. I don't feel like I succeeded in giving you what you want to see with the maf freq. Build a histogram? can you give me some more detail? Honestly surprised it didn't pull more timing than it did...Originally Posted by SiriusC1024
I need to study up on combustion instability, never heard of it...
I sure appreciate the help
GBull
I wonder about my 24 year old cats, 205K miles. Is there a chance they have become restrictive and that would affect timing?
Yes, there is a chance. It's somewhat unlikely if you haven't noticed the other major side affects, low power, rotten egg smell during or right after WOT. Several ways to test them: remove them from the exhaust and go for a test run. Mount a psi sensor before the cat, run a few different rpm tests and record the psi before the cat. Then put the same sensor after the cat and run the same tests, you should see little to no psi difference. The sensor can be a mechanical type gauge. Some people like to shoot the parts cannon at it, others like to diagnose it, whichever way you chose is up to you.
I see. Come up on spark a bit. Log this please. You got MAF (Hz) in there. Wideband doesn't seem to be logging correctly.
I will reinstall wideband today also, that's why it's not working..
What is the purpose of the slight dip in timing in the 4000 range WOT ?
He is taking an educated guess at your ign. timing table. ICE engines typically (including this type of combo.) do not need or want as much ign. lead at the point the engine is most efficient, which is at peak torque. In your case, he is taking a good conservative educated guess in attempt to curb peak cylinder psi as to not induce knock.
Basic rule of thumb, as rpm increases, so does ign. lead (or advance). As rpm increases and efficiency goes up, ign. lead can stabilize or come down to a point when efficiency decreases, cylinder psi decreases, then you can add more ign. lead.
I forgot to mention. Go to Scanner>Vehicle Controls & Special Functions and clear LTFT's.
will do. I am forced to use an older version on an old laptop... So I have to make your changes by hand. Think I found em all. Those full tables take a while.
That makes sense thanks!
Hooked up my wideband and gave her a go... super rich, barely started, no leaving driveway.
I figured. If airflow isn't right then that'll put spark in the wrong spot on the cylair axis. Clear LTFT's and try again with this.
On the LM1 what formula are you using? LM1 custom isn't consistent with voltage.
Last edited by SiriusC1024; 10-29-2024 at 09:05 PM.
Geez its been so long I don't remember how I even set it up... can I view my equation for that in the scanner?
Funny... I've now asked enough questions to become a "tuner" after 10 years of perusing this site.
I see you put things into SD mode so the low spark table was used. Still knocked a little. The fueling looks ok to my newly granted "tuner" eyes. It all seemed to fall in line.
Can you see a deficiency in my wideband by looking at this scan?
Idk why but the latest log file won't load anything. The previous does.
Give this a try
Still nothing. No channels and no telemetry. Does it show anything when you open it?
nothing.png
It played back fine for me. Weird, I just played it to the end with no problems on my old laptop but it would not play on my desktop that runs a newer version. The previous ones do play on the updated desktop... It is 26 min long? I'll go out and do a shorter one and post it. I wont forget trim reset... the only change is I hooked up the wideband to the system and added two histograms.
Last edited by GBull; 10-30-2024 at 02:20 PM.
seems to be the length, did a short test that played on my desktop. After lunch I will run a shorter scan and post.
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