Isolating EFI variables... How?

Thor Johnson johnsont at falcon.cs.mercer.edu
Mon Apr 7 05:07:37 GMT 1997


The EFI code I've built (68hc11) uses look up tables for everything:

  Base fuel time = [MAP]    - Basic MAP operation
  Modify by *= [Cyl#][RPM]   - Cylinder airflow fine tuning
  Modify by *= [IAT]         - Temperature compensation

*= indicates a multiplication factor, [] indicating a lookup table index

>From these, I have a basic carburetor w/o an acceleration circuit.  I 
think I need to add a lookup table for delta-throttle, but am unsure how 
to do this: offset, a multiplication factor, or both?

Do I need to account for the current throttle position in some form?  Or 
how about engine temp (the intake is PVC, so I didn't think I'd need it 
at first, but...)?

Lastly, is there any nice method to do the data reduction/ table 
generation?  I'm fudgin the figures by hand now but its slow going.  
Ideally, I'd like to use the oxygen sensor to "suggest" modifications to 
the tables, then wehn I reconnect to my laptop, decide which 
modifications are used.

An aside - does anyone know a good way to implement a fuzzy algorithm 
using a lookup table? 


I'm beginning to feel overwhelmed here!

Thanks!


                Thor Johnson
          johnsont at falcon.cs.mercer.edu
     http://falcon.cs.mercer.edu/~johnsont
                                                    
         Have you seen the WarpMap lately?                    
    http://falcon.cs.mercer.edu/~johnsont/warpmap  





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