LEM G3 AdaptaLink pinout?

[JFB]

Hi.

The other day on the track, I lost power.  Turns out, it seems my NA8 Supercharged Miata lost cylinder 3 and 4.  I have tested a lot of stuff and it seems to me I'm having a ground issue with injector 3 and 4.  I have 12v to both injectors, but looks like something is preventing the injectors from grounding and therefore sending fuel in the cylinders.  I have used the test injector function in PCLink: injectors 1+2 function as advertised, but 3+4 are silent.

I am now following wires from the injectors to the AdaptaLink, but first I am trying to test continuity in the wires.  Problem is I cannot find a pinout for the adaptalink I have.  Therefore I cannot test continuity from the AdaptaLink to the injector...  I have looked on the manuals page, but the adaptaLink for a Miata doesn't seem to match the one I have.  I have included a few pictures.

A pinout for AdaptaLink would be appreciated.  Thank you

JF

[Adamw]

That would have to be our Miata adaptalink (ALMX) as far as I know there was nothing else similar.  So Pinout on the car side should be standard NA miata.

To confirm you can slide it out of the case and it should be labelled LEM G3 - Miata/GTX

[JFB]

Hi Adamw,

 

Thank you for your reply.

I am having an issue with injectors 3+4 not sending a signal to the actual injectors.  I have tested all the wiring from ECU to injectors and it all checks out.  The continuity is there, and there is 12v to the ECU.  The ground of the ECU itself is also working.

 

When I use PCLink to test the injectors, I am able to see that testing injectors 1+2 works as it should.  When I try to test injector 3+4, nothing happens.  This makes sense since the injectors aren't working when I start the engine.

 

I am thinking there is an issue with the ECU or AdaptaLink.  What else can I do to narrow down the problem?  Can my ECU be fixed if it's indeed the problem?

 

Thanks.

 

JF

[Simon]

On the MX5 adapter the injectors are paired. 

What you should see is that when testing drive 1 or 2 you will have 2 injectors firing at a time in a pair.

Injector 1 test should fire Cylinder 1 and 3 injectors.

Injector 2 test should fire Cylinder 2 and 4 injectors. 

Check on the adapter if you have connection between Pin 1 and 3, and Pin 14 and 16 

 

[JFB]

By pins 1-3 and pins 14-16 you mean if there is continuity between greens and purples?

[Adamw]

Correct.

[JFB]

Hi Adamw,

 

I've finally gotten around to putting my engine back together.  I started it.  Still only two cylinders.  At least it starts! lol.

 

I've tested continuity between one green and one purple, then the other green and other purple.  There is no continuity between green and purple on the ECU pins.

There is continuity between the two greens individually.  There is also continuity between the two purples individually. Is that what was meant to be tested?

What's next?

Thanks,

 

JF

[Adamw]

5 hours ago, JFB said:

There is continuity between the two greens individually.  There is also continuity between the two purples individually. Is that what was meant to be tested?

Correct.  This would mean the ECU will be outputing a pulse on all 4 of those pins.  Inj 1&3 will pulse together and Inj 2 & 4 will pulse together.

You could try moving the plug off injector 2 and plugging it onto inj 3 then do the inj test again and see if injector 3 still doesnt work.  This will confirm if it is wiring or the injector.