Twothirtyfour

Apologies if this question has been asked. New to forums, but have searched for days before asking.
my MS2 that I bought prebuilt has a switch for either 2 VR sensor wires, or 1 crank hall sensor. From what I understand, most people running miatas use the JS10 extra input for their cmp cam signal, and the hall sensor input for the ckp cam signal.

After much trouble shooting, I learned that the person who built the MS2 never included js10 for “personal reasons.” He then conveniently linked his eBay add for the extra aftermarket compatible sensor. https://www.ebay.com/itm/29312409627...84.m1555.l2649

Can I run a stock miata with only 1 signal? And do I need to buy a toothed wheel, or is a signal from the cam enough?

borka

iTrader: (1)

Dont all NA miatas run off a single cas in the back of the valve cover?

Martin Y

Yes, but with two signals coming from it.

I think the answer to the OPs question is that yes, it can run, but only in batch injection because it doesn't know the phase of the pistons. But doubtless someone more familiar will be along shortly.

Twothirtyfour

It's one CAS but there are two wires for two signals. I believe they're both optical sensors, 1 hole and 4 hole.
I'm just wondering what my best option is moving forward, considering my JS10 only works as an output, and not an input.
Should I get a toothed crank wheel?
Should I make custom trigger settings and use my 4 hole sensor?
Should I attach both wires and to my input, to get another hole, then mess with trigger settings?
My soldering skills are below par.
Do I have to get a new ms2?
Other options? I'm not a big fan of batch injection, I'd atleast like to know what cycle my cylinder is in (even if it's not necessary).

Also please no hate, new to this car stuff.

Twothirtyfour

Bump

Twothirtyfour

Okay, I have an idea. Replacing the CAS optical disc from a 4-1 to a 24-1, removing a tooth from the set of 24, and using the sensor that senses the 24 effective teeth, then using custom toothed wheel settings in Tunerstudio. I'm pretty sure this will work, but now I have a new question.
I can't find anyone making miata trigger discs. Are 4g63/sr20/other nissan discs compatible with the miata's? https://yoshifab.com/store/high-reso...gger-disk.html

I found someone who has done it before, but I don't know where he got his disc. https://forum.miata.net/vb/showthread.php?t=444326

Page 71 and 119 lead me to believe that it is likely compatible, as well as page 70's matching sensor pins. http://www.msextra.com/doc/pdf/MS2V357_Hardware-3.4.pdf

I have a 1990 short crank. a crank trigger wheel will be alot of work, so I'd prefer not to go down that route.

So, which trigger discs are compatible with miata, if any?

Twothirtyfour

Update: So it seems that the sr20's and KA24s 50mm discs are compatible with 1990 miata CAS discs. I'm currently at a cross roads;
I can buy an AEM sr20/KA24 50mm disc, with rectangular holes.
I can buy Yoshifab DSM (4G63?) disc with evenly spaced square holes/teeth.
I think I'd prefer the square holes, since I'd be less likely to screw up the going high/low/edge settings, but it's too much of a risk since I cant find if its compatible or not.
I think I will just buy the AEM sr20 disc, remove a tooth, and cross my fingers
Thanks for all the helpful comments and super-useful advice, friends!!