sd2 running like crap- wideband reading rich and still adding fuel?

[haywire4130]

i posted on a thread a few weeks ago about my car intermittently cutting out while driving and generally running horribly. it was running perfect last season and has run poorly all this year (lots of flat spots/hesitation/cf was all over the place). when it would malfunction the wideband would randomly go way rich to way lean a few times and it would load up, run on like 2 cylinders and stall. a couple times i got a code 42, but not every time. after a few wot restart attempts (to clear the flood) it would restart and run normally. i connected the laptop to it the other night to try to figure out what was up. with the engine warm i logged it idling and i looked at some of the tables. i noticed the target a/f table does not match the numbers i entered in the grid (not sure if they ever did when it was running good). also i noticed it was adding a bunch of fuel even though it was reading richer than target.

not sure if gnomes came in this winter and messed with my setup or i have a bad connection or defective component somewhere? the wideband sensor is a year old with about 3k miles on it, the map sensor is from 08 and came with the alky kit and i tried grounding it straight to the battery with no change. the last time i reflashed the pl was when the updated sd2 chip (the one with with dfco and spool mode enabled) was installed sometime last year, whatever version that was . anybody see any glaring issues? last year it was extremely consistent and ran really crisp and fast, i had it pretty dialed in and the cf was +/- 2 during most driving. i dont trust my car and havent driven it much this year, need to get it straightened out.

 

[Pronto]

I've got a spare ecm if you want to try it. It's not set up for a Powerlogger but you can do that to it if you want.

 

[TurboTdr3.8]

Injector offset is on 0 for some reason , adj that and see what happens , that would make it add fuel because of the leanness

 

[haywire4130]

I never added any injector offset from day 1, it always ran good so I never needed to change it. My understanding is offset would add (or subtract) fuel from the entire tune to compensate for discrepancies in actual injector flow rate vs advertised?
Thanks for the offer pronto, if it comes down to swapping known good parts around I may take you up on it! For now I am leaning toward corrupt software or the aforementioned gnomes ;-)

 

[TurboTdr3.8]

I never added any injector offset from day 1, it always ran good so I never needed to change it. My understanding is offset would add (or subtract) fuel from the entire tune to compensate for discrepancies in actual injector flow rate vs advertised?
Thanks for the offer pronto, if it comes down to swapping known good parts around I may take you up on it! For now I am leaning toward corrupt software or the aforementioned gnomes ;-)

My chip had some offset setting in it from when I received it from Eric , I do not believe it come set on zero unless the setting was corrupted when you loaded it .

 

[TurboTdr3.8]

From the instructions with the chip

Injector Offset
Adjusts for injector opening/closing speed

I believe mine had about 25 to 30 , cause I did play with that number some .

 

[haywire4130]

Interesting stuff... I'll look on some of my old logs and see if a number got lost somewhere? Are you running some exotic injectors?

 

[TurboTdr3.8]

Interesting stuff... I'll look on some of my old logs and see if a number got lost somewhere? Are you running some exotic injectors?

No I just running 75lb low injectors with a modded ecm .

 

[haywire4130]

Just checked a bunch of old logs, all had zero offset. I'm not saying that adjusting it won't make my car run better, I'm just trying to figure out why it was running fine and suddenly went way out of tune with no changes whatsoever, and developed an intermittent problem of going pig rich and stalling at highway speed.

 

[TurboTdr3.8]

My car started acting up some the other day trying to cut of at idle , found out the pl had slipped some and removed it and cleaned terminals and all it back to normal , The pl connections need to be very good and clean .

Just for giggles try putting a number in it and try it and see if it improves and you can always put it back , that is what I like about this system you are in control . I understand what you are saying but it does not seem realistic setting at 0 . just my 2 cents

 

[haywire4130]

I will absolutely do that, I'm in bed with strep throat but I'm hoping to be mobile tomorrow and will give it a go. I was leaning toward a bad connection at the pl, especially since my garage is uninsulated and experiences big swings in temp and humidity (I get fog on the inside of my gauges occasionally) so I could totally believe a little corrosion may be on the ecm-pl contacts. That's next on my list of things to check, soon as I can swallow without seeing stars that is!

 

[Eric Stage I]

The default injector offset in your chip is 24. It will get richer when you change it (if it was at 0) and the correction at idle will come down, maybe even too much. Might need to retune idle. I would also smooth out the VE numbers around idle.

 

[Pronto]

Maybe a thin swipe of dielectric grease for the connections?

 

[haywire4130]

Before I try to tune anything I am trying to figure out what went wrong/why does my car keep cutting out? The title of this post is deceiving, my fault. I only mentioned the cf being way off because it was never like that before. I'm gonna have at all the connections and see if I can get it to run for a few days without shatting the sheets then I'll start making changes to the tuning.

 

[haywire4130]

http://www.turbobuick.com/forums/th...-log-finally-please-help.414273/#post-3425416

this is the original problem, i wasnt able to get a log for a while so figured id post a new thread.

 

[haywire4130]

I apologize if I came across as an ass in this thread, I was ready to riddle the car with .45 holes in frustration. Today I verified all my ecm/pl connections then had at the tuning.
As recommended I set the injector offset at 24, trimmed a bunch of fuel from the idle quick adjust (was still pulling max fuel), increased the injector size to 65 since it was pig rich all over the place, then started trimming fuel from the top left quarter of the ve table.

Car is right back to being an undriveable tire - frying monster!!! Tune is in the ballpark again now, close to where I had it last year. I'm still scratching my head as to how it "went" so far out of tune with zero changes (I even trickle charge it on a battery tender every winter, so it didn't lose power or anything). Put about 40 miles on it tonight, great cruising weather, and car runs fantastic, nice and crisp like when I first put the chip in, c/f is + or - about 2 under most normal driving. Only issue now is a little lean dip on tip-in and its still fat in the midrange and up top. Lots of power left on the table! Guess I'll run it and keep an eye on it. Any thoughts what happened?

 

[TurboTdr3.8]

Good to hear you got it sorted out and tearing up the pavement again .

 

[Pronto]

Glad to hear your back to it running good. Sounds like you might want to keep a saved file of the tune in separate location just to have incase it loses it again.

 

[haywire4130]

That's on my to - do list, have a dedicated computer for the car. I actually have an old laptop I could use but the battery is crapola and only lasts 10 minutes I admittedly haven't been keeping up with the sd2 progress lately, wonder if there's anyone using a tablet or something small and cheap?

 

[huntsg]

I've hooked up to a tablet. It's a dell running windows 8.1. Works great.