Step 65 confusion

BlackHat · Post by **BlackHat** » Sat Jul 29, 2006 12:14 pm

I've tried looking through the extra resources (searching, stickies, etc.) but for some reason the search is returning a ton without my keywords and couldn't spot anything in the stickies.

I'm assembling my MS and got to step 65. I want to run ignition from the MSEFI, but noticed it referred me to MSnS website for assembly instructions. Where are the assembly instructions for a MSnS setup? The only thing I see on the MS assembly is MSII instructions... maybe I'm blind, but a point in the right direction would be greatly appreciated =)

BlackHat · Post by **BlackHat** » Mon Jul 31, 2006 5:55 am

I found where I'm supposed to be to get the info on the ignition module, I think, but I'm having trouble understanding how to wire a V3 MS for distibutor ignition. (Here is where I'm looking http://megasquirt.sourceforge.net/extra/setup-msns.html)

I'm using a dual optical CAS wheel. I can pull a square wavelength signal from the cas. I want to run a MSD 6a ignition module and I have a relay box.

The instructions I see on that MSnS website seem to indicate the High current driver is already set-up. I'm not so sure I even need a High Current driver if I'm using the relay box, but I figure there's still got to be some wiring that needs done. Or is there?

BlackHat · Post by **BlackHat** » Mon Jul 31, 2006 11:31 am

I've been digging around the instructions/manuals and forums and I have found on the MSnS site a small diagram of putting a jumper on the - lead of D14 and connecting that to IGN... Is that all there is to it? I swear I'm trying to find the anwser but it's not terribly clear and I've been trying to make sure I'm doing this all right.

Any help at all would be appreciated!

woh · Post by **woh** » Mon Jul 31, 2006 12:46 pm

BlackHat,

There are several ways to do the ignition. You can use an optical trigger from your distributor to trigger MS and then have MS control your coil directly if you have a distributor. Here are some questions that will help us give a clearer answer:

Do you have fuel working? (without using MS to control ignition.
Are you planning to use a single coil? as apposed to wasted spark multiple coil without distributor.
How many cylinders?
Is the dual CAS wheel the original setup?
What are you running? MSI, MSII, v3?
Do you have a scope?, DMM?

It would help tremendously if you give us a diagram of what you have?

I can pull a square wavelength signal from the cas

Can you give a little more detail. Is it 0 to 12V? At about 10deg BTDC is it a rising or falling edge?

BlackHat · Post by **BlackHat** » Mon Jul 31, 2006 1:08 pm

No, Fuel is not working. I'm just trying to finish MS assembly. step 65 refers me to MSnS website and I couldn't find the substitute for that step.

Single Coil with stock dizzy and MSD 6a

4 cylinder (KA24E, Stock 89 Nissan 240sx engine)

Yes, the opto CAS is stock. It takes in a 5V, Ground, and has 2 signal wires. One is for a 4 slot inner markings (on the wheel) and the other is a 360 slot outer wheel. I've been told the 360 is not necesary for MSEFI, so that will be a dead wire. The 4 slot has a larger slot for cylinder one. Basically, if you were to look at the square wave it would look something like this:

|------|_______|--|________|--|______|--|______

Sorry, that's the best I have for a diagram.

No I do not have a scope (or know what a DMM is)

As far as I am aware the rise of the wave lengths is TDC, although I am not 100% on that. I'll be able to test that out much better once I start running the MSEFI wire harness (when I start cutting into the factory harness). I believe the CAS was designed to signal with ground (sensor reading a slot reports as a ground) as we had to make a circuit triggered with a PNP sensor (Collector triggered by signal wire from the CAS connector) which lit an led. I know, rudimentary but my friend and I aren't that knowledgable about electronics or this level of automechanics =/.

That's most of what I know, and I'm willing to dig for anything else you may need.

woh · Post by **woh** » Mon Jul 31, 2006 3:44 pm

Black Hat,

On step 65:
1. do not connect JS10 to IGN, instead if you are going to use the internal coil driver connect igbtOut to IGN.

2. Do a,b,c; Connect as in the second part of d. IgbtOut to IGN

I am assuming you will not need the MSD 6a. I actually don't know what it is.

I suggest when you get the assembly done, run the ignition without MS and connect pin 24 to the neg of the coil. None of this (step 65) will be needed to run the car with fuel only. These connections will be needed to have MS control the ignition. The final connections and jumpers will look like this below. The connection at the distributor (pin 24) may be different depending if the 'square wave' has a rising or falling waveshape at about 10deg BTDC. But you can figure this out later.

BlackHat · Post by **BlackHat** » Mon Jul 31, 2006 7:23 pm

woh wrote: I am assuming you will not need the MSD 6a. I actually don't know what it is.

Actually, I will be needing it. The MSD 6a ignition module will be driving the MSD coil. I've seen some instructions for wiring it, and that's where I came up with the D14 to IGN jumper. At least, that's how I assumed it worked.

Sorry for the confusion on that point.

woh · Post by **woh** » Mon Jul 31, 2006 8:15 pm

ok, that sounds reasonable to me. That would eliminate the need for the coil driver Q16

I'm not much of an expert on the MSD unit, but I expect if you have the coil driver of MS v3.0 loaded you can use it instead of the MSD unit. That is the bottom part of the diagram. But I'm sure what you are suggesting will work as well and will eliminate the need to run high current in the cable to MS.

BlackHat · Post by **BlackHat** » Tue Aug 01, 2006 5:06 am

Kinda wish I understood what the MS did with the coil a little more a while back.... I just bought the MSD 6a not that long ago =/ oh well, the price of ignorance.

Just to make sure I've got this right in my head. D14 shows a signal everytime there is supposed to be a spark event? That would make it pretty easy on the MS...

It just seemed too easy....

woh · Post by **woh** » Tue Aug 01, 2006 5:44 am

That's right.

the input to pin 24 tells MS the position of the crank. The trigger is when the output of U3/R13 goes from 5V to 0V (IRQ-1). That is called the trigger angle. MS then computes when the plug needs to be fired and sends that to R26/Q6. From you can route it to you own coil driver, or use the installed coil driver Q16

BlackHat · Post by **BlackHat** » Tue Aug 01, 2006 6:28 am

Going the MSD 6a ignition Module route would you suggest even installing Q16? Or would that just a useless addition if I was using my own coil driver? (in otherwords, should I ignore the regular MSEFI coil driver steps and just do D14 --> IGN?)

The only reason I ask is because there seems to be other steps where they suggest installing 2 different setups and using a jumper to choose one. This particular case doesn't sound like it should be one... but I never know =)

woh · Post by **woh** » Tue Aug 01, 2006 7:42 am

Install everything. It is simple and easy. You may need it at a later time.