MS3X and sequential injection
 

I am installing a 99 motor into a 97. The previous owner had this engine in his 93. The PO had installed the CAS from his 93 and removed the trigger wheel. The PO has installed the 93 cam pulleys as well.

I have the following ready to install:

1. MS3X programmed for sequential injection
2. EFR6258
3. ID 1000 injectors
4. Vishnu Dual feed rail
5. Toyota COPs.

What will I need to run sequential injection on this engine?

Do I need to replace the 93 CAS with my 97 CAS?
Do I need to get a trigger wheel and sensor?

I have read thru forums but am still not clear. Any help is much appreciated.
:noob:

If you have the early NA optical CAS you can get a new wheel from DIYAUTOTUNE that should be able to offer a single signal for sequential injection. This will also offer higher resolution for approximated crank position
Optical trigger wheel for Nissan SR20DET or KA24DE DIYAutoTune.com


If you switch out the optical CAS for the later hall effect NA version, you have to lob off all teeth but one, which, i'm not sure.

additional info:Our Friend CAS

Or you can add an oem trigger wheel up front for crank position, and use the modified CAS for ignition or install a BP4W/MSM cam gear on the intake side and try running any 99-00 or MSM code for MS3 that might accomodate the stock sensors.

I'm having the same dilemma. I have all sensors available to me except the hall effect CAS, but I don't which route to go. If I use the stock BP4W sensor, I'll have to grind off two nubs on the intake cam gear, and still have to figure out how to setup the 36-1 trigger wheel

Seq. works with the 90-95 CAS or an unmodded 96-97 CMP/CKP or the 99-00 CMP/CKP.

Do you have any of those options? the Stock 99-00 setup being the best.

The NA CAS does provide both CMP and CKP signals required for sequential fuel and ignition, so if you want to take the most minimalist approach, what you have installed on the engine now works. However the CAS is driven off the timing gear, as such it is subject to slop which results in timing jitter. Since it looks like you're going with a pretty boss setup, I would go ahead and reinstall the 99 crank and cam triggers on the engine. The 99 CKP trigger is bolted directly to the crank and is much more accurate than the signal from the NA CAS. Option 3 would be to return to all 99 spec but use the FM 36-2 trigger wheel instead of the OE 4 tooth wheel. Theoretically that would result in the greatest accuracy of all the 'plug in' style options.

Perhaps you can help me figure out what to do with my setup. I want to use the 99 sensors but was under the impression I had to grind off the twin stubs on the cam gear so only one pulse per rotation was identified. Is this accurate?

I also have the supermiata damper/36-1 trigger wheel; is setting this up as easy as counting the offset angle from TDC and entering the wheel type?

Also as far as wiring, can the 99 sensors just be paired up to an NA's CAS wiring? Can power/ground be common for both the CMP and CKP with the signal wire be tapped right to the original CAS wiring?

I haven't swapped the car yet, but am trying to address these questions so the project doenst hang.

Color me dumb. :brain: I am NOT

What is CMP and CKP?

Going to all 99 spec would involve the following right?

1. Remove the existing CAS
2. Install the 99 Intake CAM with trigger
3. Install the 99 CAM sensor (I still have the 99 valve cover)
4. Install the FM 36-2 trigger wheel
5. Install the 99 crank sensor (hopefully do not have to change oil pump)
6. Any wiring change?

This was the case on the MS1, and ONLY on the MS1.

With the MS2 and MS3, the OEM NB sensors and plates can be used without modification. Simply tell the ECU that you have a '99-05 Miata engine and you wish to run fully sequential (four injector channels) and the ECU will do all the rest automatically.


Now, if you bring any other crankwheel into the mix (such as a 12T or 36T wheel), then you will need to physically modify the cam gear (99-00) or camshaft (01-05) to take it down to just one pulse per rev. But so long as you use the stock crankwheel, you can also use the stock cam/gear with no mods needed.

EDIT: I have been informed that a recent code change supports 36-2 in the FM configuration with the stock NB CAS pattern.

Frankly, I wouldn't bother with an aftermarket wheel here. The prediction on the MS3 is pretty damn accurate.

FTFY.

Abbreviations.

Generally, CKP means CranKshaft Position, and CMP means CaMshaft Position. In some communities, CKP is also called Ne, and CMP is refered to as G. (I have no idea what these stand for.)

In the case of an NB, the distinction between CKP and CMP is fairly obvious.

In the NA, where both signals come from the same sensor (the CAS), we typically call CKP the signal on the White wire, which gives four evenly-spaced pulses per camshaft revolution (one pulse per ignition event), and the CMP signal the one on the Yellow or Yellow / Blue wire, which gives two uneven pulses per camshaft revolution (one short, one long) which determine absolute engine phase but are not used for event-timing.

Do I still need to install 99 OEM trigger wheel instead of 36-2?

yes. i assumed that would already be installed...

just need stock 99-00 sensors/wheels/whatever

Thank you kindly. Looks like I'll have to re-evaluate my setup and find a way to remove the pulley now.

Wiring these sensors into an NA6 is just a matter of splicing into the existing cmp/ckp leads of the stock CAS?

switched power, ground, and the signals back to the ECU.

Yeah, snip off the CAS connector, split the +12V and ground into two and run them to both sensors, then run the CKP wire from the CAS to your crank sensor and the CMP wire from the CAS to your new cam sensor.

You guys are....amazing.

No modification to the cam trigger is needed IF

• You use the stock NB 4 tooth crank trigger (or)
• You use the FM 36-2 crank trigger

If you use any other crank trigger, it will need to be paired with a 1 tooth cam trigger for sequential operation of injection and/or ignition.

The FM crank trigger is theoretically more accurate than the stock 4 tooth crank trigger. I would expect the greatest delta to occur during sudden RPM transients (hard accel/decel). However I do not know if there is a real world advantage or not. I have the FM wheel on my 01.

unfortunately the SuperMiata damper uses a proprietary trigger wheel and will not fit the FM 36-2.

The tooth configuration is also slightly different otherwise I'd have no qualms with chopping an additional tooth off to match the FM setup.

This may seem rudimentary but why exactly couldn't you turn the SuperMiata 36-1 into a 36-2? Even if the tooth spacing is slightly different, can't you set the MS to compensate?

https://www.miataturbo.net/attachmen...ine=1384799486http://949racing.com/images/products...erwhl_damp.jpg

I mean seriously... its a wheel missing some teeth :dunno:

For preset trigger configurations (for example selecting 99-00 miata in megasquirt) can you edit field for tooth #1 angle? Also is there a code for the 99-00 miata to run the FM 36-2 wheel, I thought that was geared toward Hydra users. If I can use whatever makes a motor run on stock BP4W sensors and trigger points and a 36-2 with an adjusted offset angle, then I guess my inquiry is moot.

Again, I'm grasping at straws to understand how to make this setup work. I'm still finishing the motor and the MS3 is sitting out until swap. It's apparent that I've been confusing methods between different MS iterations, and apologize for any spread of misinformation.

I'm still on MS1 and stock 1.6L so I cannot access many of these to familiarize myself.

From the photos, if the wheel is positioned at TDC tooth #1 appears

shy before 9 o'clock on the FM trigger wheel

~1 o'clock on the SuperMiata trigger wheel