Ms3X - critique my wiring and a few minor questions

[dcg9381]

Question:
MS3 manual indicates where to ground a shield for a VR type crank sensor (to pin 2 on the MS3 connector) - where do I ground a similar shield for the cam sensor?

Project is a Toyota 2.4L 2RZ motor (largely the same as the 3rz). Wasted Spark - two coils (2-tower type) - they are logic level and have built in igniters. 36-2 Crank sensor (VR type) + Cam sensor (VR type).
Injection will be sequential.
IAC is 3-wire PWM type.

2rz_wiring_diagram_MS3x-v1.jpg

[dontz125]

Your CMPS shield should go to the CKPS +ve wire; that's an AC signal. I would suggest the shield go to an unused MS-DB37 ground pin, perhaps #8. Do *not* connect it to the ground wires going off from MS-DB37 #14-19.

Along the same lines, your CMPS -ve wire should be grounded separately from the main ground bus. I would suggest MS-DB37 #2; that way you have the CKPS on #1 and the CMPS on #2, and the CMPS shield on #8. Easy to keep track.

You have 3 wires coming off each of your two 4-wire coil packs; what is the #2 wire (Black / Yellow) for? Should it go to the MS signal ground, MS-DB37 #7?

I don't see an issue on the MS3X-DB37 wires, but note that it is reversed to the MS-DB37. Be careful not to wire up your connector backwards!

I don't see any reference to relays; I assume that you've seen the recommended relay wiring on page 17 of the MS3X manual.

[dcg9381]

CMPS = CaM Position Sensor
CKPS = CranK Position Sensor

Note, I have 3 wire CMPS and CKPS sensors from the factory, They appear to be shield, -ve, and +ve (I assume).
The CKPS is on the MS3 DB37. The CMPS is on the MS3X connector. I'm missing something or don't understand exactly what you're saying if you're indicating that the shield of one connects to the other.

An "unused" DB37 pin implies to me that it's unterminated - but you're indicating that they are ground - IE #8. 8 - 13 show up as unused in the docs (http://msextra.com/doc/ms3/General_Pix/v3-wiring.png). What I read is that the shields should be grounded closest to "source" - I'm not entirely sure what that implies, unless it's grounding to the motor. You're saying do not ground the to common ground... But where do those 8-13 pins terminate if they're ground?

Coils:
I have 4 wire coils. I only have to address 3 wires. The 4th wire is a factory "diagnostic" wire if I recall right. They are left unterminated... I'll see if I can fish out the wire from the connector.

I noted the reversal on numbering between MSX37 and MS37 connectors, but thanks for calling it out anyway... I had to check it more than once. I got out my magnifying glass when wiring the DB37X. The DB37 is pre-wired for me, I'll actually just be pulling off pins - it's DIYAutotune stuff.

You're right on the relay setup. The final harness is a bit more complicated, as I used bits of the factory wiring which already have the associated relays... I just didn't want that mucking up my diagram. The fuel pump is on an appropriate relay, MS just switches the relay to ground (switch side, low amps). Coils should be relayed also with ignition, I'm still working that bit out.

[dontz125]

*face palm* "Your CMPS shield should *NOT* go to the CKPS +ve wire". Sorry for the brain typo.

On the main board DB37, pins 1, 2, and 7-19 are all connected to the ground plane. The CKPS and CMPS -ve wires and shields should be connected to dedicated ground pins,but should NOT be connected to the harness ground wires.

[dcg9381]

No problem, just a sanity check. Thanks for the help.
This doc helped too:
http://www.msextra.com/doc/general/grounding.html

Basically the recommendation is to use the MS ground, but not to tie to 14-19 which are also shared to chassis.
Basically any pin, in the following list: 1,2 or 7-13 as ground, as these are not shared to the harness ground... There is continuity between ping 1-2 and 7-19, but we're trying to minimize the voltage drop during cranking.

[dcg9381]

So does it change anything if the shield wire is connected at the sensor? My understanding is that you terminate only one end?
The 2RZ crank position sensor has 3 wires - one appears to be shield that grounds at the sensor.

[dcg9381]

Superseded diagrams for the 2rz can be found here:
http://www.2rzturbo.net/?page_id=613