SD2 E85 Tuning Help Central Illinois

mtocrs1

Mtocrs1
Joined
Mar 16, 2007
I need help guys. I have Eric's SD2 chip and can't seem to make heads or tails of what's going on. Is anyone willing to help me tune this thing. I am willing to pay. Looking for recommendations for a shop with SD2 experience or will pay for remote tuning support. I send log you help me with next steps.
I currently can't get the thing to idle without surging if the AFR is leaner than 12:1.
I would just order a chip from Eric but don't want to lose flex fuel capabilities.
I feel defeated as I have tuned with HP tuners on my G8 without issues.


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Hey Eric,
I will get some logs this weekend with a target Idle AFR of 13:1
Ill get one with the base fuel settings idling smooth at 12:1 AFR with the AFR correction maxed at -10.
Will also do the following:
Log with injector offset value lowered, this alone will not change AFR correction % in my situation.
Log with idle fuel adjusted to get AFR correction within +?- 5%
Log with adjusting VE table to bring AFR correction within +/- 5%
Anything else you can think of let me know.
Thanks
 
Hey Eric,
Here are some files I got today, Still surges if I try to bring the AFR anything leaner 12:1. The last file I advanced the timing in the 800 RPM column of the timing table. It seemed to help or maybe my eyes were just crossed at this point. Unfortunately I didn't realize the changes I was making on the fly in the VE or timing tables wouldn't show up real time in the logs. I didn't realize the last value would be shown for the entire recorded run. Next time I will save a new recording for each change.
Can you please take a look. What do you think my next step should be?
 

Attachments

  • colde start 12 on crank fuel-3-13.dat
    537.4 KB · Views: 119
  • idle fuel 97- slight surge 12.5 AFR.dat
    1.4 MB · Views: 137
  • idle fuel 95- surge 13.0 AFR.dat
    362.5 KB · Views: 108
  • modified ve bad suege died.dat
    1 MB · Views: 112
  • Adjusted timing and ve surge reduced.dat
    1.5 MB · Views: 130
No function other than having something else to compare the the wideband to. The more data the better.

Did the car idle fine before the sd2? Was anything else changed? Like injectors or fuel system stuff?
 
It's a fresh engine with new injectors and fuel pump. Before the engine swap it idled fine with a turbo tweak.
I just can't wrap my head around what could be causing it. I don't see anything out of the ordinary. Map signal looks good. The only thing I don't get is that during the surging the IAC stays flat. You would think it would try to compensate.


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I would start by making the VE the same number in the idle range. Right now the VE is cycling up and down around 50 to 54%. Bring up the lower numbers, in other words, make it all 54% so it doesn't cycle. Also do the same with spark.
Start there and see how it goes.
Also, what cam do you have?
 
I would start by making the VE the same number in the idle range. Right now the VE is cycling up and down around 50 to 54%. Bring up the lower numbers, in other words, make it all 54% so it doesn't cycle. Also do the same with spark.
Start there and see how it goes.
Also, what cam do you have?
The cam is a full throttle 210/215 Roller.
I will make the adjustments you recommended and report back.
Thanks for the help so far.
 
Hey Eric,
Don't go to the end of the file. For some reason it makes PL wig out and you have to close PL with task manager.
Please take a look at this latest file. Around 1890 seconds is a good point in the log. Adjusting VE and timing to the same values definitely helped.
I do still have a surge but not as noticeable. Do you think I should try turning off closed loop? Seems like AFR correction is diving the change but maybe its reacting.
What would you recommend?
 

Attachments

  • Adjusted VE and timing same values.dat
    4.3 MB · Views: 137
Looks like it needs a tad more fuel at the lowest MAP reading, around 40kpa. You could add some VE there to help out.
You don't have the fuel pressure up higher than 43psi (no vac) do you? Where is it currently set?
 
I'll have to recheck. It was set at 43 line off but I did add the fuel pump Hotwire ground strap since setting the pressure.


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Rechecked and the fuel pressure is at 47psi on the mechanical gauge with the line off.It will not go below 47. The pump must flow to much for the factory return line with the Hotwire ground installed.
So is there another map/table I need to adjust to compensate besides VE?


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Happy guy today! Found the root cause of this surge and inability to tune it out. My brand new brake booster has an internal diaphragm leak. I started to notice that when I would step on the brakes the engine pitch would change. Release the pedal engine pitch would change.
The diaphragm must hold a certain amount of vacuum, leak, seal, leak etc.
I removed the vacuum line at the booster and plugged the line. Engine stopped surging.
Go figure. Thanks for the help guys, it is much appreciated.
Log attached. More tuning is needed but this was a major hurdle.
 

Attachments

  • Booster Unplugged.dat
    962.4 KB · Views: 109
No function other than having something else to compare the the wideband to.
SD2 does in fact use the stock 02. there is a feature called narrow band tracking. Any time your target AFR is between 14.6 and 14.8, the PL will close the loop with the stock O2, instead of the wideband.
 
SD2 does in fact use the stock 02. there is a feature called narrow band tracking. Any time your target AFR is between 14.6 and 14.8, the PL will close the loop with the stock O2, instead of the wideband.

Yes Roger that. You do have the option to use it.
 
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