ignition coils?

[Bruce]

While not DIY, FAST (formerly Speedpro), has what's called eDIST.
Uses the LS1 coil near plug coils.  Just add a cam synch., signal to your
system, then wire as necessary.   Not a ccheap answer, but still an answer,
where all the details are worked out.

MAFs are a whole lot more complicated then folks seem to admit.  For the
time effort energy, why not just go MAP?.
It also might be easier to swap ecms to something else entirely, rather then
poor so many hours into what you have.
Bruce

From: "Howard Chu" <hyc at highlandsun.com>
Subject: ignition coils?
> Sorry if this is off-topic, but you guys seem to be the ones who'd know -
> I'd like to get hold of a set of pencil ignition coils, to try to use them
> in my '97 Probe GTS. I.e., I want to convert my current electronic
> distributor ignition to direct ignition. I've worked out my trigger
circuit
> but I haven't found anyone who sells the actual coils at a rational price.
> Do you know where I might be able to order these things?
>
> I was originally planning to switch the output from a CDI kit into the
> individual coils,  because then I wouldn't have to worry much about dwell
> time at high RPM. But I'm not confident that I can switch a +/-400V output
> reliably (using TRIACs?) so I think I'm going to have to go back to an
> inductive design.
>
> (The basic plan here - mount 6 Hall switches in my distributor cap, and a
> small permanent magnet on the end of the rotor. Disconnect power from the
> distributor, remove the internal coil. Using Allegro A3141 Hall switches,
> triggering CD4044 flipflops to turn on a transistor to select an
individual
> coil. The stock ignition trigger signal from the ECU still controls
> charging/discharging the selected coil. Except, if I scrap the CDI kit, my
> switching logic gets more complicated. The A3141 switch is
> momentary-on. At the moment I use the flipflops such that the Hall switch
> turns "on" the "current" cylinder and turns "off" the "previous" cylinder.
> That means I have 60 degrees for coil charge and discharge to occur.
> Unfortunately, there's not enough time at high RPM to get a full charge,
so
> I have to be able to select a coil and keep it charging thru 120 degrees
> instead...)
>
> While browsing thru the archives for this list I noticed a discussion on
> replacing an AFM with a MAF. This has been on my mind too, since this
Mazda
> KL engine also uses a pretty restrictive volume measurement sensor. The
MAF
> and VAF transfer functions are pretty much completely opposite in slope. I
> decided to try just going MAF -> ADC -> EEPROM -> DAC. No
> processor/controller of any kind, just a fixed mapping in the EEPROMs.
> Unfortunately this setup doesn't take temperature into account, and the
> stock ECU uses the IAT to convert the VAF input to mass. I started looking
> at analog multipliers to take this into account, but the IAT's output is
> only linear for part of its range, which tells me I need another EEPROM to
> map that out, and a CPU of some kind to do the compensation. I've left
> things alone for the time being; I think it will make more sense to just
> reprogram the stock ECU to accept a MAF input. Does anyone have any good
> info on programming a Mazda OBDII ECU?


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