Where to start?

[Bruce Plecan]

ECM Bench details:

Lawn Tractor Battery power supply-trickle charger-no ground loop
    problems.  Must remember to fuse everything.  Too small of
    power supply, and with a scanner, voltage variance can cause
    injector PW to vary.
555s for VSS, and rpm.  VSS is usually 2,000 ppm, or 4,000 ppm
    DPDT switch for VSS on, P/N is grounded as vss signal applied.
    DPDT switch for ignition pulses so MAP signal changes when
                the engine starts.  (figure 6,800 rpm redline for v-8)
    On/Off for memory clear.
    On/Off for ecm, injectors, 555s, and misc on.
Disable malfunction coode 43 (ESC)
Disable VATS if it applies
IAT, and Coolant temp sensors use a 10K pot, and a 1K.  Finding
     C/L Learn temp enables much easier with the 1K.
MAP works fine with 10K
O2 Feedback, have several types around, ie 1 trigger per crank
revolution, or one triggered by individual ignition events.  Feed this
to a 555 and then steady state you can adjust the 555 to maintain
a 128/128 BL/Int.

Injector loading doesn't seem to affect Pulse width of injectors.
Solder, and heat shrink everything.  You won't beleve what a tangle
of wires you'll wind up with.
  For the price of a couple switches, and using ganged pots might
as well set it up for doing 2 ecms,
  Use an ignition module
The 148 MAF signal is 5vDC  27-147 Hz , 50% duty cycle
I'd feed the VSS RPM MAF all thru  flip flops to get the 50%, and
use that on everything.
  On the P-4s If ya can afford a Diacom get it. I makes the work so
much easier.  Thou a scanner will work just fine.
   Use LEDs for outputs, and label them with pin # and item, since
will vary by ecm.
   Use actual ecm connectors.
Bruce

 I don't have a detailed plan for the bench yet, just a
>bunch of pots and a few 555's. Might get a couple trashed (cracked >tip)
fuel injectors to throw on there as well. Does anyone here have >details on
a bench setup, or possibly that could be one place to >start? I've got the
factory manual for my '89 motor, so I've got a good >idea on what the
sensors comprise. So, that's probably how I'll >start... Just wondering
>if anyone had this stuff documented anywhere.
>Feel free to throw comments, flames, whatever at me. ;)
>-Andrew M