EEC IV reprogramming

[Brian Warburton, c/o Turbo Systems Ltd]

Note: These are my own opinions based on my experience with Ford,
and elsewhere. Just because they may differ from someone elses
doesn't necessarily make either of us right ..... or wrong. 


>>> >  Q:  are you wanting to know the 8061 opcodes because
>>> >      you would like to 
>>> >      change the way the eec handles the information it receives?   ..
>>> >  ... or do you just want the eec to 'respond' differently to a set of 
>>> >      inputs?     
>>> >

The only reason to know the 8061/8065 opcodes is if you intend to
re-program the way the EEC works, if you just want to change the way
it responds for a given set of input data, you only need to change
the calibration, i.e. the data in the maps etc. 

>>it happens that the eec gets 1 and only 1 timing signal from the tfi 
>>unit.  it is called the pip (Profile Ignition Pickup ??).  on a 4 cyl the 
>>output of the pip is 45 - 55Hz @ 1000 RPM, on a 6 cyl the output of the 
>>pip is 45 - 55Hz @ 1000 RPM, and finally on an 8cyl the output (and 
>>you guessed it) is 45 - 55Hz @ 1000RPM (oh: the duty cycle on all of these 
>>should be 50%) these numbers are true for all ford engines except the 
>>SEFI 8cyl (the SEFI 6 cylinders are the same.  the 8 cyl must need 
>>tighter timing indexes)

I missed the start of this discussion so I'm purely speculating on
the original question/inquiry but here goes anyway.

The EEC's only see one Crankshaft Position Sensor signal, but where
it comes from depends on the age of the EEC. Early EEC's used a
sectored wheel in the distributor which produced a square wave of
frequency of Number-Cylinders per 2-revs with a nominal 50%
dutycycle unless SEFI was used wherupon there was a "short" tooth.
The spark was output by a TFI unit.

The later (and to the best of my knowledge) all current EEC's
including the EEC-v utilise a 36-1 tooth wheel for CPS which is
pre-processed by a unit known as the EDIS (Electronic DIStributor).
The EDIS converts the 36-1 into a 2 pulses/rev 50% dutycycle square
wave which is then fed into the EEC to be used for RPM and injector
timing calculations. The EEC sends a PWM signal to the EDIS
defining the spark advance required, and the EDIS unit then times
out the signals to the coils (wasted spark).  This gives a more
accurate spark delivery as the EDIS has access to timing data
which is updated every 10 crank degrees whereas the EEC only gets
timing data every 90 degrees. 

>>what i gleened from this is that the pip does 2 things:
>>1) it lets the eec know how fast the engine is turning (frequency alone)
>>2) it gives a base signal to be sent back to the tfi after being delayed 
>>   a bit.  this delay or phase change (realitive to the pip) is what lets
>>   the eec control timing, but indirectly, the tfi is doing _most_ of the 
>>   work.
>>

The return signal from the EEC to the EDIS is unrelated to the PIP.
It purely indicates to the EDIS unit the amount of spark advance
required. 

>>mike wesley has said ..
>>    "you'll see that ford does not use the CPU as it was designed (to be 
>>    used?)   . . . they waste so much CPU it's pitiful"
>>

Having spent from 1986 to 1994 full-time consulting to Ford (both in
Europe for FOB and in the U.S. for NAAO) on EEC-iv/EEC-v design and
programming, I'd be genuinely interested to hear the basis for those
comments. 

>>i'm betting he's refering to the fact that the CPU is just looking up a 
>>bunch of tables. (remember superchips .. just tables no code)
>>the cpu only has to look up injector "on time" and SPOUT "phase shift" 
>>for any certain rpm, mass air, and engine temperature and its job is 
>>done.  add on a few more bells and whistles and its done.  A real 
>>programmer would use the CPU to "compute" these outputs not look them up.

I'll deliberately pass on the "real-programmer" comment, suffice to
say that I'd love to see the algorythm that could calculate
required/optimium Spark Advance under all conditions to enable the
engine to meet its operating criteria of power, driveability and
most importantly emissions given the input data available to an
EEC, i.e. CPS timing data, engine temperature, air-charge
temperature, throttle position, EGO data and Cylinder-ID to name
the significant ones. It's (relatively) easy to determine/calculate
the spark required for optimium power, but the compromises made to
meet emissions and driveability makes it a whole new ball game. 

>>moral is: if you want to make your own controller (and i'm interested) 
>>all you have to do is figure out the "TFI secret" and half your job is 
>>done.  the injector pulsing is a piece of cake compared to trying to fire 
>>a spark at the proper time ... every time. 
>>

No secret to the EDIS, it knows the required spark advance from the
EEC and has accurate and regularly updated timing data for current
crankshaft position, what else do you need to deliver an accurate
spark ?

>>i think you CAN use any eec with any other engine (all the fuel injectors 
>>are in banks of two ... choose the proper size and fuel pressure ... pick 
>>the proper TFI ( is there a difference??)  and adjust for wiring 
>>differences.. <;-)

I think you'll find the "TFI" (EDIS) units are all very similar, 
the differences are in the EEC. You can't just switch EEC's for
different EEC's, they are generally electrically similar (not
identical) but totally different in terms of code and calibration
content. 

>From my understanding of Mikes box, you can map out the internal
PROM and use external memory which would let you run any
program/calibration you wanted (and had copies of) in an EEC.
I'd guess you'd need a permanent piggy-back type board with an
EPROM and address decoder PAL on it (a la Super-Chips) to make
permanent changes tho'....... 
 
I for one would be interested to hear more about these boxes,
especially if they're to become commercially available. I could
find a good use for one ! 

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Brian Warburton,   "Still searching for the perfect curve....."
email: bwarb at turbo.win-uk.net
                               Advanced Automotive Electronics Ltd,
                               Van-Nuys House, Scotlands Drive,
                               Farnham Common, England.  SL2-3ES
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~