How to MegaSquirt Your Nissan 280ZX Turbo

Directly driving the coil with the MegaSquirt-I PCB 3.0 and MSnS-E 024s9 or later or the MegaSquirt-II

Application: 1982-1983 280ZX Turbo, or conversions using the 82-83 turbo distributor  

Updated 10/20/2020 – link to HybridZ.org changed

These same modifications work for the ’84-’89 300ZX, both turbo and non turbo.

Level of control:  Full Standalone EMS– Fuel and Ignition Control

There is already a great write-up by ‘mobythevan’ at Hybridz.org on how to MegaSquirt the 280zx turbo using the MegaSquirt-I PCB2.2 ECU, combined with an HEI-4 module, but what about the more recently released PCB3 ECU?  Certainly you could use it the exact same way and follow the same document combining the MS with the HEI-4 module and end up with the same result, but what about that snazzy new IGBT High Current Ignition Coil Driver that’s built into the PCBv3.0 ECU?  I was recently contacted by a customer that wanted to try and go this route, and I told him I’d make the necessary modifications and document the process for others to follow…  so here we go!

Note – want to trigger a distributorless ignition or sequential injection from the stock distributor? We now offer a bolt in trigger disc that gives you that option. It needs slightly different mods and settings; see this article for how to set it up.

ECU Modifications

It’s choice time, MS1 with MS1/Extra firmware, MS2, or MS3.  You can use an MS3 with the MS2 mods shown here, although to take full advantage of the MS3’s capabilities, it is better to use our L28ET trigger disc upgrade to allow sequential injection.

These modifications use a BIP373 ignition transistor, sold separately from the kit.

Using the MS-I PCBv3 or V3.57 with MS1/Extra firmware

  • This is assuming you are starting with an ECU built up like I build my assembled MS130-C MegaSquirt-I PCB3.0 units.  If you are building your unit up from a kit you can implement these changes during assembly.
  • Make sure it is set for Hall / optical input
    • For a V3.0 board, connect TachSelect to OptoIn, TSEL to OptoOut.
    • For a V3.57 board, put JP1 in the 2-3 position and J1 in the 1-2 position
  • Flash ECU with MSnS-E version 024s9 or later. 
  • For a V3.0 board, jumper IGBTOUT to IGN to send to IGBT ignition coil driver signal out of pin 36 on the DB37.
  • Remove C12 and C30.  (Only needed when triggering from the – terminal of the coil, which you are not)
  • Remove D1 and jumper it, or just install a jumper wire across it’s leads.  (Only needed when triggering from the – terminal of the coil, which you are not)
  • Cut out R57 if fitted (this won’t be there on my units though).
  • Get a 330 ohm 1/4w resistor and cut the leads down to about 1/2″ at each end. Maybe a bit less.
  • Tin each end of the resistor with a bit of solder.
  • Cut a 5″ piece of hookup wire (22ga is fine) and strip just a 1/8″ or so. Tin the stripped wire with solder.
  • Melt the tinned wire tip to one end of the tinned 330 ohm resistor tip and let it cool.

  msnse_led17-d14_thru_vb921005.jpg (67542 bytes)

  • Heatshrink wrap this wire/resistor assembly.

msnse_led17-d14_thru_vb921007.jpg (79951 bytes)

  • For a V3.0, use this wire/resistor combo to jumper the ‘top’ (top as in when you facing the silkscreen side of the PCB, with the text so that you can read it normally) lead of R26 to IGBTIN on the opposite side of the PCB.
  • For a V3.57 board, this wire goes from pin 7 of the U1 socket to IGBTIN instead.

msnse_led17-d14_thru_vb921011.jpg (149401 bytes)

That’s it!

 

Using the MS-II PCBv3 or V3.57 ECU

  • Build the ECU up to trigger from the Hall/Optical Input (all of my MS230-C units are by default configured this way).
    • For a V3.0, connect TachSelect to OptoIn, TSEL to OptoOut.
    • For a V3.57 board, put JP1 in the 2-3 position and J1 in the 1-2 position
  • The only change is to enable the IGBT High Current Ignition Coil Driver Circuit to directly drive the coil. 
    • Remove the jumper from JS10 to IGN or the center hole of Q16 (if exists)
    • Jumper IGBTIN to JS10
    • Jumper IGBTOUT to IGN (V3.0 only)
    • If you do not have a BIP373 transistor in the Q16 slot, install it.

    That’s it!

    Note – if using MS2/Extra, you can also build the board as shown in the MS1 example. You will need to change the spark output pin from JS10 to D14.

 

Wiring

The input side of things will be the same as mobythevan’s setup– it’s the output side of things that will change.  Here’s a diagram of how to wire it all up if you’re laying out your own wiring harness. This diagram assumes you are splicing the connector from the OEM Nissan wiring – color designations are for the Nissan wiring harness, not the MegaSquirt wiring.

 

 

And alternately, here’s a diagram for how to wire up the relay board if you choose to use it:

Thanks to Chris Lupkin for permission to use this drawing

Distributor Wire Colors in the OEM Wiring Harness

Colors of the wires on the distributor side of the 4 pin round connector, versus on the harness side.  You can connect in from either side.

Dizzy Side  Harness Side Purpose
Red Black / White 12v+
White Green / Black MS Trigger (to Pin 24 on DB37, or Relay Board TACH terminal)
Green Green / Yellow not used
Black Black Ground

On our current harness for standard MegaSquirts, the MS trigger wire is the white wire in the shielded tach input, and the black wire in the shielded tach input is a ground. You can power the distributor from the same source where the MegaSquirt gets power.

TunerStudio Configuration for MS1/Extra

For now, continue to refer to Mobythevan’s documentation for MegaTune configuration of the MSnS-E firmware.  You can use the .msq files from PCBv2.2 implementations with this setup– you’ll just need to reconfigure the spark output so that instead of coming from FIDLE it’s now coming from D14 (aka LED17).  You can do this from inside MegaTune.  Select the ‘Code Config’ Menu, then select the ‘Codebase and outputs function’ option.  Set ‘FIDLE function’ to ‘Idle Control’ and set ‘LED17 function’ to ‘Spark Output’.

On the ‘Spark’ menu choose ‘Spark Settings’ and set ‘Spark Output Inverted’ to YES.

If you use someone else’s .msq file, I recommend you check the MSnS-E firmware version the .msq file was built on. You cannot always use a file built on one version of MSnS_E with a different version– it’s best to use the .msq files with the same version of the MSnS-E firmware that it was built on.

 

TunerStudio Configuration for MS-II B&G code

Start with a trigger angle of 90, and adjust from there with a timing light.

Ignition input capture should be set to Falling Edge.

Coil charging scheme should be set to standard coil charging.

Spark output needs to be set to going high / inverted.

Do not enable dual spark or wheel decoding.

 

TunerStudio Configuration for MS2/Extra (based on 3.3.3 or later code)

Spark mode: Basic Trigger

Trigger angle / offset: Start at 90 degrees. Adjust with a timing light as needed.

Ignition input capture: Falling edge

Spark output: Going High

Number of coils: Single coil

Spark A output pin: JS10

Dwell type: Standard dwell