MS2, ka24de confusion

[intransit.cc]

hi, first post. relatively new to megasquirt. i apologize in advance for any incorrect terms or dumb questions. I swear i have tried to research and figure this out on my own before making this post haha.

set up is as follows:
89 nissan 240sx w/ 94 ka24de, high compression, ITB using custom manifold and silvertop 20V 4age TB's
msd blaster 2 coil
Megasquirt II V3.0 (MS230-C) w/MS2/Extra release 3.4.2
tuner studio lite V3.0.05
Megastim V2.21
diyautotune 10ft db37 harness wired as per basic instructions on their site
diyautotune nissan optical trigger disc in the distributor

i already typed this out once over an hour and had it accidentally deleted so i may end up being a little brief the second time around. okay, so...

according to the DIYautotune "how to megasquirt your 240sx" article things seem pretty straight forward for hardware.

Using the MS-II PCBv3 ECU
Build the ECU up to trigger from the Hall/Optical Input (all of our MS230-C units are by default configured this way).
The only change is to enable the IGBT High Current Ignition Coil Driver Circuit to directly drive the coil.
Remove the jumper from JS10 to IGN (if exists)
Jumper IGBTIN to JS10
Jumper IGBTOUT to IGN
(This will enable the BIP373 Ignition Coil Driver)

That’s it!

great, simple. i can see and understand all of this and what is happening.
now, maybe i made a mistake in going for the optical wheel they provide, but i as informed that it would be helpful and picked it up. under the instructions for that is where i start to get confused. so:

Using the MS-II V3.0 or V3.57 ECU with MS2/Extra

Make sure it is set for Hall / optical input (TachSelect to OptoIn, TSEL to OptoOut).

check. thats all set up and good.

Cut out C12 and C30. (Only needed when triggering from the – terminal of the coil, which you are not)
Remove D1 and jumper it, or just install a jumper wire across it’s leads. (Only needed when triggering from the – terminal of the coil, which you are not)

okay, this is where i start to get confused. so, c12 and c30 are already gone, and d1 is jumped. but, where it says "only needed when triggering the negative of the coil". so i have my wiring set up like the diagram provided with the harness, with pin 36 (brown wire) going to the negative of the blaster 2 coil and the positive going to 12V. that would lead me to believe that the coil is being triggered by pin 36? or am i misunderstanding something? maybe itis referring to the oem coil and ignitor setup, but even then that seems wrong to my knowledge of the ka. i switched to the blaster coil to simplify my ignition as i was under the impression that the BIP373 acted as the ignitor but perhaps i have made it more complicated. or i am completely misunderstanding part of it.

Cut out R57 if fitted (this won’t be there on my units though).

check. already not there.

Connect S12 to TachSelect using a 1K resistor. (Or you can use a 1K pull up in the wiring, between pin 24 and a 12V source.)

check. already wired the pull up in the harness.

If you want sequential coil on plug (or sequential injection with the 3.2.1 code), you’ll also need a second trigger input. Solder a 1K resistor onto a length of wire, and cover the resistor with heat shrink tubing. Connect this resistor-on-a-wire combination from JS10 to SPR1.

I am not going for COP so i am ignoring this step.

Solder a 470 ohm resistor onto a length of wire and cover with heat shrink tubing. Run this resistor-on-a-wire from the 5 volt terminal in the proto area to SPR1.

so, SPR1 already has a length of wire going from it to (i think) JS6 (upper board covers the area). so would i be tapping into SPR1 as well or removing that length of wire?

Connect a 0.1 uF capacitor from JS10 to SG or the proto area ground.

again, JS10 is already going to IGBTIN, so i am i doubling up or missing something?

Install the spark output of your choice. BIP373 or QuadSpark output mods are two possible choices. OEM Nissan SR20DET ignition modules require 5 volt logic level ignition outputs.

is this referring to the BIP373 already installed in Q16 or am i installing a second one somewhere?

I'm sorry if this has been covered. i tried searching the forum for any similar post and i've been through the MS2V30 hardware manual but couldn't come to a positive conclusion. thank you for taking the time to read and for any information that could help, if there is any more information or pictures i can provide to give more clarity i will assist as quickly as possible

cheers!
-cole

[Matt Cramer]

The article we have is for the standard trigger disc and a distributor - it appears you're getting it mixed up with some notes on using our add on trigger disc for COP operation.

[intransit.cc]

The article we have is for the standard trigger disc and a distributor - it appears you're getting it mixed up with some notes on using our add on trigger disc for COP operation.

you are right, I have notes from both articles present. the reason for that being that I DO have the diyautotune nissan optical trigger disc installed in my distributor. I do not plan on going COP in the near future but I was under the impression that the diyautotune disc helps clean up the resolution and was also usable for a standard distributor and single coil set up, but perhaps I was misinformed or misunderstood. that leads me to two questions then:

so from what I am taking from your comment, the instructions under the diyautotune Nissan trigger disc page are dealing with COP set ups. being that I am distributor and single, aftermarket, coil I should be ignoring those instructions and going along with "how to megasquirt your 240sx"?

and, did I make a bad call on installing the diyautotune trigger disc when I am distributor and single coil? should I stick with the oem disc until I decide to go COP?

thank you for replying, Matt

[slow_hemi6]

The DIY disc should have no trouble as an input for a single coil installation. Just have to configure it correctly in tuner studio. Would be a toothed wheel, 12-1 at crank speed. You would have to check with Matt as to whether there could be any rotor phasing issues though. I have no idea about that.
DIY wrote

Only needed when triggering from the – terminal of the coil, which you are not

You wrote

"only needed when triggering the negative of the coil"

Do you see the difference, DIY is talking about a coil signal INPUT as you might do for a "fuel only" install not being necasary. You missed the "from" and thought it had something to do with the output to the coil, which it does not.