[Spridgets] 1275 efi

Glen Byrns grbyrns at ucdavis.edu
Tue Nov 13 08:35:02 MST 2007

I had a very productive weekend of tuning on the EFI system.  The "Autotune"
function works great.  I can catch the laptop screen out of the corner of my
eye while I'm driving and watch it working away like a demon perfecting the
fueling table.  After a 50 mile drive with little bursts of "boost" and some
steep uphill, much of the table is now populated with "corrected" values and
the car runs great.  The plugs look PERFECT after the drive and the gas guage
didn't even move off "F".  There is absolutely no overrun when you shut this
system off.  I can't wait to see what kind of mileage I'm getting now, but I'm
absolutely sure I'm getting better mileage based on the plug cut.  I don't
ever recall having the motor respond so well across all gears and RPM as it
does now.  No lean spots, no rich spots, great acceleration without a

This week's agenda is to erase the original code on the CPU and load in the
expanded code that will allow me to hook up the ignition to the computer as
well.  I will be able to put in any custom advance curve, start-up timing
adjustment, and manifold pressure indexed boost retard.  The expanded code
gives me a 16x16 table for fuel values and for spark timing.  Sweet!  I built
all the necessary bits into the computer for spark control at the start,  now
its time to take the next step.

Glen Byrns

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