SD2 extremely lean just off idle. Log inside

gunslinger

Member
Last week, for some reason my tune ate itself. Cells 1-4 copied themselves into cells 5-8. It barely ran and was extremely lean.
I got that straitened out, but I still have an extremely lean condition just off of idle, and a little lean at idle.
It's done this for a couple years, but not to this extreme. It stumbles, and misfires just at this point. Let it idle, and it's fine, get past this point and it's fine.
This morning I richened the whole tune up, especially at idle, and captured this log while driving to work.
I'm getting pretty frustrated with this thing. It runs differently from day to day, and has left me stranded twice now.
 

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Eric Stage I

TurboTweak Guy
Can you give me your chip# (or name so I can look up the chip)? Also, on the help tab of PL, the "about PLC" button will show the version of software you are running. It looks like you might have one of the first versions and it may help to update first, before working on the tune.
 

gunslinger

Member
My name is Eric Schmidt. I bought the SD2 chip when it first came out, and you sent me the updated version.
I"ll have to check when I get home as to what version PL software I'm running.

I made a few changes, and it's running a lot better, but the lean spike around .8v TPS, is killing me. Stop and go traffic sucks!
 

BobbyBuick

Well-Known Member
have you tried changing your injector offset ,static fuel pressure, or tps idle settings a little to see if it changes anything
 

gunslinger

Member
have you tried changing your injector offset ,static fuel pressure, or tps idle settings a little to see if it changes anything

I increased the injector offset, replaced the ECM, checked all of my grounds several times, I've been all over this car trying to find out what's going on.
I haven't changed static fuel pressure because it's rich everywhere else. It's just at idle, and just past idle.
It gets rich with an electrical load too. If I turn my headlights on at idle, CF goes from 150s to 120s.

I checked my PL software, and I'm running 2.5.2.
Is there a newer version?
 

gunslinger

Member
how is your MAP sensor powered? (thinking the lights interaction)

B
5V reference off of ECM. Followed the instructions on the Vortexbuicks site.
You might be onto something though. I noticed today that the MAP was erratic when it was lean on the hwy. It was bouncing between 22-34Hz. I wrote it off to vacuum pulsation due to the lean surge.
I'll try to get another log in the morning on my way to work.
 

BobbyBuick

Well-Known Member
i use actual target AF in parameter 2 (idle) i have it set to 129 so the idle AF ratio is 12.9
3 and 4 i have set 97
might try that it works good for me
 
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