MS3X Nissan VQ37 Development

[sjl008]

**Please note: This thread began HERE**


PLAN: Start to finish, Nissan's 2008 3.7LV6 VQ37 with VVEL & VVT.
ECU: MegaSquirt-III (V3.0 DIY board),MegaSquirt-III Daughterboard w/MegaSquirt-III MS3X Expansion Card.
Current Platform:
Engine test stand for development, once 'Tamed', put in my JEEP.
Current Status:
- Board fully assembled, tested "OK" as far as I can tell, connects via usb-Serial adapter.
- Wiring harness married to factory harness and plugs.
- Have I started it yet....NO, need to find or learn how to decode factory 36 -2-2-2 Crank Position(Angle) Sensor @ flywheel. Or, install my own on the crank pulley. (36 teeth spaces total, every tenth tooth has 2 teeth missing leaving no tdc reference)

( I'm sure ppl will wonder if I've thought it all the way through and YES -- I have, down to the Cam's variable valve lift and duration mods that will eventually need solving... )

NOW I've set it up with semi-sequential injection NEGITIVELY TRIGGERED, COP wasted spark <5vdc logic level triggered direct off 3X exp card........ Is this correct way so far?.... need to know please.

[prof315]

Yes you are correct.Your MS will ground the injectors to pulse them and send a 5v trigger to your coils .

36-2-2-2 is a supported trigger pattern though it may be somewhat vehicle specific.

[jacky4566]

Is this the VQ37VHR with VVEL? Are you going to try and use the valve lift for air control or convert to full throttle body?

[sjl008]

Is this the VQ37VHR with VVEL? Are you going to try and use the valve lift for air control or convert to full throttle body?

I've converted it to 'Single' Throttle body (Hitachi) that has a twin plug TPS. The VVEL I think fully closes the intake valves on shut down, so I will eventually have to build a simpler circuit to control each actuator -- something I'll bypass for now, until I have work out the other bugs to get it at least running.

Thanks for clearing up the 36-2-2-2, and verifying MS output polarities. Last 2 days spent making a wheel adapter that slides into the stock balancer to fit a 36-2 trigger wheel and 3-wire hall which I've had no luck getting anything read-able from.

I borrowed the VQ40 Cosworth crank pulley and 2-wire VR sensor off the race car so I'll try that setup today. (Known good operating.)

[sjl008]

Crank and Cam sensor wires:

**From 350z Shop Manual**
CRANK SENSOR:
White- Signal output to ECU
Yellow- Sensor Ground ( Pin 128 ECU )
Red---- +4~5vdc ( Pin 46 ECU )

CAM SENSOR although plug 3-wire colors are different, values appear to be same, however have not verified [yet].

So, are there any 'Vacant' pins I can run +5v from proto area to on the V3.0 board's Main plug for powering my 3-wire sensor?
YES, I just used it and created the attached .CSV log to check if my hysterious is set correctly. I also attached a pic of the board for revue(Prior to installing the +5 to CAS....?..

I will re-read the manual re: adjusting Hysterious w/pots R52-R56, but I'm I on the right track?

[sjl008]

Some Facts:

- The Nissan factory Crank sensor is a 3-wire "Magnetic HALL EFFECT" sensor.
- Cam Position Sensor "appears" to be the same; both are nippon-DENSO pt#196-4008(cam), #196-4009 (crank). However, wiring at the plug MAY BE in a different order.

After re-configuring my V3.0 board from VR to Hall, and TS settings it fires up - rough now until I dial in the tooth wheel settings more correctly.

The MS3x proto area +5v supply for these sensors currently appears to not have enough current to power both sensors AND the board (thoughts anyone?) but further investigation IS necessary.

more later - any input greatly appreciated!

[prof315]

Some Facts:

- The Nissan factory Crank sensor is a 3-wire "Magnetic HALL EFFECT" sensor.
- Cam Position Sensor "appears" to be the same; both are nippon-DENSO pt#196-4008(cam), #196-4009 (crank). However, wiring at the plug MAY BE in a different order.

After re-configuring my V3.0 board from VR to Hall, and TS settings it fires up - rough now until I dial in the tooth wheel settings more correctly.

The MS3x proto area +5v supply for these sensors currently appears to not have enough current to power both sensors AND the board (thoughts anyone?) but further investigation IS necessary.

more later - any input greatly appreciated!

Yes Nissan uses hall effect sensors for both crank and cam position... they should only need milliamps to work however... are you certain they are powered with 5V and not 12V?

[sjl008]

Some Facts:

- The Nissan factory Crank sensor is a 3-wire "Magnetic HALL EFFECT" sensor.
- Cam Position Sensor "appears" to be the same; both are nippon-DENSO pt#196-4008(cam), #196-4009 (crank). However, wiring at the plug MAY BE in a different order.

After re-configuring my V3.0 board from VR to Hall, and TS settings it fires up - rough now until I dial in the tooth wheel settings more correctly.

The MS3x proto area +5v supply for these sensors currently appears to not have enough current to power both sensors AND the board (thoughts anyone?) but further investigation IS necessary.

more later - any input greatly appreciated!

Yes Nissan uses hall effect sensors for both crank and cam position... they should only need milliamps to work however... are you certain they are powered with 5V and not 12V?

NO. I am not certain, they work with either 5 or 12v, but if I pull the +5v off the proto and use for both sensors, I get the TS prompt " ecu error" of not having enough voltage and need to cycle the ecu. This will happen during cranking to start. MOST IMPORTANT OBSERVATION was with the MS3x daughterboard removed, I witnessed my +5v pins drop to 1.98v.... which of course will not work. That was with the cam sensor plugged in.

So, I run the 36-2 wheel (34teeth minus 2) crk wheel off a cosworth VQ40 and wasted spark & semi-sequential injection.

[sjl008]

NOTE:
Since any of the VVEL motors will only increase the vavle lift and duration when necessary e.g.- free revving, under load, WOT with low MAP pressure I Know the factory separate control unit with it's ECU feedback system monitors real-time position of both cam actuators keeping them in sync, and ECU varies it's fuel VE table accordingly so creating a standalone system that can also operate the VVEL "AS ORIGINALLY designed" is not my visionary goal here.

Since my purpose is to create a solution to be able to use these motors in off-highway vehicles with a minimum cost, I want to use as much of the original components as possible. Now that it runs (Question remains +5 or 12v to Hall Sensors) I am researching the 'running loads' (mechanical forces) those ball n screw actuators are taking, and now deciding if I want/need to make them operate "On the fly". Possibly give them 3 positions I can LOCK them into, then its a simpler matter of creating 3 separate tunes for this LOW/MEDIUM/HIGH valve event and duration. Much easier and less prone to malfunction.

SYNC the left bank cam with the right bank cam then becomes much easier to do it "mechanically", than "electronically" in my opinion.

[prof315]

OK hall effect sensors can be weird. Some want 5V power some want 12V. Some will work with either ( the DIY Autotune tabbed hall for example) Chrysler had them running on 8V for years. In your case what I would do is find a VQ37 running on stock management and measure the voltage at the cam and crank sensors and use that voltage.

[Peter Florance]

It's got its own feed IIRC.
In the World Challenge Nissan, I powered off 5v, but the MOTEC had a lot of capacity

Sent from my XT1080 using Tapatalk

[sjl008]

OK hall effect sensors can be weird. Some want 5V power some want 12V. Some will work with either ( the DIY Autotune tabbed hall for example) Chrysler had them running on 8V for years. In your case what I would do is find a VQ37 running on stock management and measure the voltage at the cam and crank sensors and use that voltage.

I'd love to find a running motor to use and collect data I need. For now, I am just running the CRK sensor off my lil' proto circuit wasted spark, but today I'm trying to figure out how to get the Nissan VVT going so my plan is to have a separate supply for +5 isolating it from the MS entirely for BOTH CAM & CRK. That way it will never interfere with MS' logic board's need for stable voltage.

[sjl008]

It's got its own feed IIRC.
In the World Challenge Nissan, I powered off 5v, but the MOTEC had a lot of capacity

Sent from my XT1080 using Tapatalk

I considered MoTec, tuning I've been doing since early Bosch Jetronic days b4 there was standalone. SO, I'm a "Hands On Junky"....always interested in learning more.

Have you ever ran a Nissan V6 on MSX? if so how well was the built-in VVT circuit?

Thanks in advance!

[sjl008]

Today I discovered both Cam and Crank sensors work off +5v and both have a resistance of just over 1kOhms on the supply side AND polarity is important. I hooked up 'one' of the cam sensors, then configured VQ35DE in "Ignition options/Wheel decoder" to grab a composite of the signals my board was capturing so I posted my results:

Since the front 36 tooth crk wheel I installed is temporary, it's sensor position appears to be advanced a couple teeth in the jpg composite picture attach'd.

Is this true ?

Anyone know if the VQ37 crank's 36-2-2 (10 teeth x3, with 2 teeth missing 3times) flywheel trigger wheel is the same as the VQ35de's? gosh I'd like to know.

If so, maybe the pre-configured descoder in TS will work with my engine and I can get it done....yeah! Plz let me know if anythings upside down or something. Thanks

[Peter Florance]

Somewhere I've got a MoTeC application note that covers their wheel mode. I'll check

Sent from my XT1080 using Tapatalk

[sjl008]

Somewhere I've got a MoTeC application note that covers their wheel mode. I'll check

Sent from my XT1080 using Tapatalk

Thanks Peter, I'm sure you've been busy as everyone is these days....let me know

[Peter Florance]

Somewhere I've got a MoTeC application note that covers their wheel mode. I'll check

Sent from my XT1080 using Tapatalk

Thanks Peter, I'm sure you've been busy as everyone is these days....let me know

Actually I didn't have a note.

But I checked the VQ37 config file and it uses Ref/Sync mode 35 which is listed for VQ35.

So it sounds like they use the same wheel.

[sjl008]

Somewhere I've got a MoTeC application note that covers their wheel mode. I'll check

Sent from my XT1080 using Tapatalk

Thanks Peter, I'm sure you've been busy as everyone is these days....let me know

Actually I didn't have a note.

But I checked the VQ37 config file and it uses Ref/Sync mode 35 which is listed for VQ35.

So it sounds like they use the same wheel.

They may, haven't confirmed yet. Spoke w/moTec and a couple other 'Nissan speciaty shops that cound'nt confirm either... getting down to the wire on this project -- looks like I'll be eating all costs' and owning the motor soon but that's what I get for trying to help out someone's project thats impatient....

See if u can figure out what I posted in my other thread http://www.msextra.com/forums/viewtopic ... 31&t=65643
if u get a chance much appreciated your replies, thanks!

[sjl008]

FOR THOSE INTERESTED IN KNOWING;

YES, THE VQ35DE spark mode configured as:
"IGNITION SETTINGS > IGNITION OPTIONS/WHEEL DECODER > SPARK MODE = VQ35DE"

Using the VQ37's stock flywheel trigger wheel worked for me.....fyi

[sjl008]

Finished the MS3X build.

ALL information was accessible via MS-manuals, and TunerStudios reference guides; however, some needed deeper investigation to complete the circuitry. Not for the faint of heart or easily frustrated type. All n All feels great knowing that the end result was successful and again- Megasquirt pulled through and met my expectations, but don't trust me -- let the radical exhaust flames under acceleration speak for themselves in the attached pic ;)

Hope to get it in the car and post the dyno sheet soon.