6 replies to this topic

[Adamiata]

I bought a Mychron 3 XG Log for my 1990 Miata. I also bought the OBDII connector to connect it directly to the computer. After not being able to find the OBD connector under the dash, I found out they weren't included in the MX-5 until 1996.

So my question is: Where can I get a Can+/Can- signal from a 1990 ECU to feed to the Mychron?


Thanks,
Adam

[davew]

You can't. There is no can signal prior to OBD-II which started it 1996. You will have to wire everything individually.

Dave

[bones240z]

The ECU/Power connection coming out of the mychron3 xglog has 4 wires. Red and black for 12v and ground. Have a blue wire for tach. Is the white wire useful in anyway? Have a '90 miata. I suspect the white wire is for the CAN protocol which the '90 miata doesn't have.
Thanks in advance
Taylor

[Roger Caddell]

The white wire is a high voltage option for RPM, typically connected to the coil if that is your best option. In your '90 Miata you will not use this wire, just fold it back out of the way. All installs will use either the blue OR the white RPM connection, but never both.

Unless it has been removed, the blue and white wires should be wrapped with a tag and clear shrink wrapped with "RPM 8-50v" and "RPM 150-400v" or something like that and in the SM world, we always will use the low voltage connection to the Tach circuit of the car.

[dstevens]

With Roger's permission I could repost some of the pics of Andrew's SM data install at my place or here so those of use with steam powered ignition systems would have a reference. If you've ever put a MyChron on a kart it's pretty much the same sort of attachements/connections for the pre ODBII cars. Just more wire.

Or if you could get MyChron Mike to stop ranting about the libs long enough that might make a good "Loose Wires" post.

[Roger Caddell]

Go for it Dave.

[bones240z]

Fantastic. White wire wrapped. Thanks