Hi Tony,
"One question though.
I can understand the ICU seeing the Cranking and sending Voltage to the Coil. I still do not understand the Amplifiers job."
• Answer: The ICU doesn't send any voltage to the coil. See step 2-a below, where I used the word "trigger" as short-hand for: "causes the Power Stage/Amplifier to make and break the ground side of the coil primary winding" (12V is always on the + side). That's what "initiates" spark from the coil. (wish I hadn't said "spark" from the coil though. Hi voltage is better.)
[Think back to the old days of ignition points -- same thing.]
Question two of one;-)
"Which one of these starting sequences can Crap out and NOT leave a Code?"
• Answer: Good old 2-a)
The ICU uses these CPS pulses to trigger the Power Stage (aka Ignition Amplifier), which initiates spark from the coil.
• There is no test to see if the CPS/ICU pulses ever get to the Power Stage, or if they do, that the Power Stage does its thing. So if we get 2-b without 2-a, we have fuel pumping and injectors squirting, but no spark at the plugs, like I explain at the bottom of the canned sequence.
--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.
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