ka24e Dizzy Questions

[Steve-O]

I've been doing some research and found that all KA24E and KA24DE powered Nissan's (at least the US models) should be compatible with the MegaSquirt-2 and allow for complete fuel and spark control without giving you any trouble.

Do you mean to suggest that triggering MS2 is possible using a '95 KA24DE distributor (internal coil)? Or would one be better off swapping to an s13 (external coil) dizzy setup?

Forgive the remedial questions, but this is the only thing holding me up right now from the MS2 build instead of a PnP AEM setup. If I don't have to do a crank trigger/EDIS setup, and can make the stock ignition do the job; I'm all in.

The diagram shows no power transistor. In the stock setup the ECU signals the power transistor, which in turn amplifies the signal (per FSM) and triggers the negative terminal of the coil. Is this function now controlled by the MS2, or is a transistor still required?

And are the only connections necessary to MS2 for ignition the:

1) Coil +
2) Coil -
3) CAS +
4) CAS -
5) CAS 180* signal (square wave)

Or am I completely and hopelessly lost?

Thanks for any and all input. I don't expect to be spoon fed, but I could use a little better understanding of the Nissan ignition system. At least as far as it pertains to MS2 operation.

-Steve

EDIT: Well, I think I've answered a few of my own questions. It looks like the IGBT High Current Ignition Coil Driver Circuit can directly drive the coil. I'm just curious if anyone can verify that this works on ALL 240sx dizzies, including the internal coil ones. Do they all share the same CAS signal?

[jburgess]

im using ms1v3 not ms2... but this is what i did....

- i had to fisrt take apart the MS unit and take out some resistors and bypass other things, etc... check diyautotune.com, then goto "install articles" , then check out the "Nissan/Datsun" dizzy wire guide

the the stock nissan dizzy willwork fine (with mine not sure bout ms2)

wires out of dizzy

black = ground
red = power
white = signal 180
green = not used

white goes to a 12v pullup (12v wire with 1k ohm resistor at end) then to pin #24 on MS

the ms sees this signal and ground your coil out of pin #36 and thats it...

coil gets power all the time when ign on, from fuel pump relay, but ground wire comes from MS #36

aftermarket coil would be the best option.... im using MSD hei Blaster coil, any would work...


this is how i got mine to work

[FoundSoul]

I've been doing some research and found that all KA24E and KA24DE powered Nissan's (at least the US models) should be compatible with the MegaSquirt-2 and allow for complete fuel and spark control without giving you any trouble.

Do you mean to suggest that triggering MS2 is possible using a '95 KA24DE distributor (internal coil)? Or would one be better off swapping to an s13 (external coil) dizzy setup?

Forgive the remedial questions, but this is the only thing holding me up right now from the MS2 build instead of a PnP AEM setup. If I don't have to do a crank trigger/EDIS setup, and can make the stock ignition do the job; I'm all in.

The diagram shows no power transistor. In the stock setup the ECU signals the power transistor, which in turn amplifies the signal (per FSM) and triggers the negative terminal of the coil. Is this function now controlled by the MS2, or is a transistor still required?

And are the only connections necessary to MS2 for ignition the:

1) Coil +
2) Coil -
3) CAS +
4) CAS -
5) CAS 180* signal (square wave)

Or am I completely and hopelessly lost?

Thanks for any and all input. I don't expect to be spoon fed, but I could use a little better understanding of the Nissan ignition system. At least as far as it pertains to MS2 operation.

-Steve

EDIT: Well, I think I've answered a few of my own questions. It looks like the IGBT High Current Ignition Coil Driver Circuit can directly drive the coil. I'm just curious if anyone can verify that this works on ALL 240sx dizzies, including the internal coil ones. Do they all share the same CAS signal?

Yep-- the ignitor is internal in the S14 cars, so you won't need the IGBT high current ignition driver enabled, but should be able to fire the stock ignitor without a problem (directly from pin36). That would be the only change from my 280 article jburgess just mentioned. Just skip the mod/jumpers for enabling that IGBT and run pin 36 straight to the ignitor trigger wire.

[Steve-O]

Great, thanks for the info. I'm going to go ahead and order, since it sounds as if this will work just fine.

One little clarification though. My distributor has been modded for an MSD ignition. The power transistor (what you call ignitor) has been clipped and no longer triggers the coil directly. It is now soldered to a wire that runs out of the dizzy and triggers the MSD box. So without a transistor/ignitor, can I connect directly to the negative coil wire using the IGBT driver? Or is the transistor necessary for proper coil charging?

I can just swap to a new dizzy if need be. Just looking at my options.

Thanks again.

-Steve

[FoundSoul]

You should be able to use the VB921 IGBT driver to fire that MSD box which will fire the coil. You've got a couple of options here but that's probably what I would do.