Shainiac

iTrader: (7)

Hi everyone,


I've had my car running well for the last 4 months, but I'm tired of the occasional sync loss I'm getting with the stock CAS.
I seem to be getting one or more sync loss #11/17 while cranking (starter noise) and randomly between 3-4k rpm. Because I have a Jspec trans, 5th gear on the interstate is always over 3000rpms and this is very annoying.

Here are quick details of my build:
MS2V3.0 with Zeal board for second VR, built using DIYAutotune's guide.
Firmware 3.3.2
I'm using the proper 2 pair shielded wire, grounded at the same point as the ECU.

What I've done so far:
Installed the FFE wheel and VR sensor/bracket. Fit and finish are outstanding and well thought out. I should mention that I am using a side-mounted alternator with a homemade bracket. The belt clears the VR sensor and wiring no problem.
I made an extension harness using 2 pair shielded wire, the male connector from an old CAS and the VR sensor connector provided from the FFE kit.
I've checked continuity at the VR sensor connector to the pin at the ECU harness and both are good. I'm using Pins 24(+) & 2(-), which are the onboard VR inputs.
Attached setting from FFE

My problem:
With the extension harness and FFE's settings, I'm not getting an RPM signal. I can revert my settings back to dual-wheel, swap the connector back over to the Mazda CAS and it fires right up.

Do I need to remove the 2nd VR jumpers in the MS box for it to work on Single-wheel 36-1? So ANY physical modifications need to be done to switch from dual VR to single VR?

Thanks,
Alex

13bdarren

I think the sensor with the ffe kit need a 12v supply a ground and signal to vr in on the ms ecu. It is a hall type sensor so it should work with your existing board settings.

Shainiac

iTrader: (7)

They sell both a hall and Vr kit. I bought the Vr kit since my ecu is already built up to run dual Vr.

13b-rotary-vw

Make sure your wires are not to close to the spark plug wires. Any interference will cause this symptom. Make sure the polarities of the sensor are correct for the expected signal of the ecu ( rising or falling edge).

Shainiac

iTrader: (7)

I tried cranking with the EGI/ENG fuses pulled and still got no RPM on my laptop. With the coils not powered, the tach wouldn't move, but I still didnt get an RPM in TS.

Here is my MSQ. If anyone sees anything obvious, please let me know.

LINK TO MSQ

13bdarren

How many wire are on the new sensors. I was using rising edge for ignition capture and going high for spark output. This was with the stock fc coils and ffe fd trigger kit with hall sensor.

Shainiac

iTrader: (7)

VR is two wires. I'll check my coil settings tomorrow after work

13bdarren

have you tried switching polarity around and messing with the resistors. I got the hall sensor because I am not a big fan of the vr sensors. I seem to always have issues with them.

Shainiac

iTrader: (7)

I removed the 2nd VR output connection to the CPU. I will give that a try. Polarity I already checked, but I suppose I can double check to make sure.

13bdarren

just try flipping them around and see what happens.

Shainiac

iTrader: (7)

Sooo, I had the wires backwards.
I wired everything in accordance to my wiring diagram I made for my loom, but apparently that was wrong too.
Before I fixed the harness, I set trigger from falling to rising and inverted the offset 180. It fired right up!
I reset the settings and fixed the harness and now it runs like a champ!
I no longer get sync loss while cranking and the RPM signal is so much smoother. The stock setting of 60° was pretty close. 63° was the number my car liked best. Maybe placebo effect, but it even idles smoother. Less hunting and more stable afr.
Still too cold to see how it does under load, but I'm pleased so far.

13bdarren

Nice. This was the best upgrade I have done for my car as well.