Howdy folks:

At my wits end here and at an absolute loss.

Bought a MS2PNP (which calling it a MS2 is a little misleading when it's based off Microsquirt, but whatever) from FlowForce (note: NOT DIYAutoTune, but as far as I can tell, tomayto tomahto) for my '91 w/ '95 engine ('91 harness tho).

I cannot for the life of me get INJ2 to send a signal from TunerStudio, which explains why I'm running on only two cylinders right now.

PLOT TWIST: Unplugging the IACV causes the MegaSquirt to *lose signal and disconnect from TunerStudio*.

It's worth noting the IACV and the injectors share white-red...or is that just a herring?

PLOT TWIST: I swapped back to the stock ECU and *that doesn't work on 2/4 either*.

As a matter of fact, I de-pinned the harness to pull out yellow-black (2V) and directly pinned it onto the MS (only #2 injector plugged into the engine)

If I put it on 2V, nada. No click during INJ2 testing *or* INJ1 testing.

If I put it on 2U, click during INJ1 testing.

So it *can* signal over yellow/black, just not out of the MegaSquirt.

I am constantly suspect of my grounds as well...could a bad ground cause JUST 2/4 to drop?

 

As an update:

For whatever reason, this particular MS is outputting INJ2 on 2Y, not 2V.

It's POSSIBLE that 2V and 2Z are mapped to INJ3 and INJ4, I haven't tried.

Food for thought for the "next guy" - doesn't explain the IACV thing but whatever.

 

Not sure if this is resurrecting a dead thread, but I just ran into this same injector issue with a MSPNP2 on my Miata. It was only running on cylinders 1/3 and there was no signal to the injectors for 2/4. I finally found the injector 2 signal was being sent to pin 2Y instead of 2V just like you. I moved the pin in the harness connector over and the car fired right up on all 4 cylinders. Wonder if there is something wrong in the latest firmware.