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Josh's B18 LS-VTEC Powered 1965 Mini (27th) 
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OK, got a look at the two 2D tables... not good.

One is kinda random, which might be OK if the random bits are outside of San Diego temperatures. Yes, looks OK from 20C to 90C, maybe even all the way up to "way overheated". Not terrible, but not good. This is the priming pulse table:

Image




The other... is bad, very bad. The other is engine temperature based enrichment. The overruling factor about this table is that it should have zero influence when the engine is warmed up. I'm not here to tell you what that means on your engine, so it's flexible. I think this fits into the over protecting the user category... so it likely won't change. But it's worth not repeating this mistake:

Image




If the engine tstat opens at 95C and the coolant never exceeds that, then that's the upper flat point with no correction (100%). If the tstat turns off again at 85C and starts heating up again, this is likely the other end, and a 10C tolerance of "this is all warmed up and normal" applies. It could be a bit wider than that (some overshoot on each end). It could be a bit higher than that. It could be a bit lower than that. THERE MUST BE A FLAT SECTION @ 100% (no correction). Period. This curve does not have such a flat section, so AFRs will wander between tstat open/close events following this enrichment. Not good. Worse, if the engine actually runs well under this tune, when this curve is corrected it's going to be a bunch leaner than before. Also not good. IE, if we put a fixed curve into this device without changing the VE curve to suit, it'll likely not run well.

Solution steps:

  1. Get the engine running and fully warmed up
  2. Let it oscillate on the tstat for a few minutes cooling and heating, or on the fan if the tstat is wide open all of the time, same deal.
  3. Record min/max for "warmed up" and "not cold" and "not overheated" based on the above movements.
  4. Change the curve to include these values in the AXIS with values of 100% for each. The engine will go lean by 10-12%.
  5. After this if the engine doesn't run well, add more VE% everywhere that's needed until it runs nicely again.
  6. Do another rip by jumpering the load header and running the loader and choosing rip all. Send it to me.

Further notes:

  • Priming pulses for lower temperatures than you can currently tune should be greater than or equal to your lowest temperature tuned value. I would extrapolate upward rather than go flat.
  • Ditto for engine temperature enrichment, it must keep rising at some rate, and it makes NO sense for it to fall off again as temps continue to decline.
  • Never tune if ETE is not 100% (no correction) AND the engine is not fully warmed up (these should match!) as you're just screwing up your tune making it *worse* not better.

Fred.

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Tue Jan 21, 2014 2:30 am
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On site and underway! More news as it comes to hand.

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FreeEMS dev diary and its comments thread and my turbo truck!
n00bs, do NOT PM or email tech questions! Use the forum!
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Wed Oct 25, 2017 1:13 am
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Didn't seem to be able to change timing offset with old firmware and fresh emstudio, and some protocol items missing from 4 year old firmware, so opted to apply points from post on previous page to the setup and try to start from scratch with the latest instead. This is what I did in reverse order:

commit 1d4a213b95780031cd18f6317364c4fa3ced1828: Point 6 increasing tolerance to 200/150 where thread says 310/152, skipping: 4 (physical change on engine) and 5 (no longer needed).
commit 422e6da445c451b3746d37a8dabaf6361caeaa99: Skipping point 2 from same list as Josh said coils need SFA dwell time. This commit takes care of point 3 by reducing timing in the cranking row and using a default table that makes more sense than dead flat.
commit 47abe9746951cd70bc062eb46847e096d8eda210: Change from 60 to 80 percent flat VE for base for Josh's mini. Forum point one in post 37500 says 85, but this'll do.

Will give that a try and go from there. Possible outcome, timing still doesn't change and we're measuring it wrongly off the primary of the coil.

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DIYEFI.org - where Open Source means Open Source, and Free means Freedom
FreeEMS.org - the open source engine management system
FreeEMS dev diary and its comments thread and my turbo truck!
n00bs, do NOT PM or email tech questions! Use the forum!
The ever growing list of FreeEMS success stories!


Wed Oct 25, 2017 7:22 pm
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