Going from Batch to sequential injection on a 92 miata with MSPNP Gen 2
 

Is going from batch injection to sequential injection as simple as running a single wire from the 2nd injector and another single wire from 4th injector, and connecting the first new wire to pin 8 and the second new wire to pin 9 on the MSPNPs additional harness. Then enabling sequential injection in the correct places in TunerStudio?

I'm asking because I found a lot of info about going to sequential injection, but nothing that was specific enough that I felt comfortable cutting wires on my harness before being sure.

you need un-pair your injector harness.

then you need to run two wires to INJ C and INJ D outputs.

you wire INJ C to cly4, and INJ D to cly2.

INJA and INJB should be wired to the OEM harness at cly1 and cly3 respectively.

then change untimed injection (or semi-seq.) to fully seq.

you'll have to retune fuel.

Thank you!

I never got an exact answer myself when I did this, but I wired mine a bit different and it still seems to work.

I wired cylinder 1 and 2 through the oem harness and I wired cylinder 3 and 4 to the mspnp gen db26 connector. then change the settings to sequential/semi- sequential in tunerstudio.

I don't know why wiring like this still works good. It idles smoother than when I was running Batch inj. sooooo yeah that's my input :dunno:

Also in the mspnp2 documentation it talks about specific jumpers on the board that will control what injector and how many injectors each channel can control. I didn't move any jumpers and it still works. :confused:

Are these the correct pins for the MSPNP Gen 2 with 1.2 mainboard

pin 6 - CANBus high :: CANH = INJ C
pin 7 - CANBus low :: CANL = INJ D

I believe with the 1.3 main board INJ C is pin 18 and INJ D is pin 26. But I'm not seeing the same details for the 1.2 main board.

Im not sure about the 1.2 board, its not very detailed in the manual. I have a 1.3 and yes that is what I wired to. I connected injector 3 to pin 16 and injector 4 to pin 26.

Yes, I noticed just how much clearer it was with the 1.3 board and the 26 pin connector.

Does anyone know the pins used for the miata 90-93 harness? Per the suggestion from diy I tried sourcing one through a salvage yard. They quoted me 95.00 for a connector with 6" of wire coming off of it. And the local dealer said mazda does not stock or even specify the pins they only sell the complete harness.

Pins for what?

You're at the wrong yard. Try a "U-pull" sort of yard; they often have much better pricing.

For the 1.2 board you have to repin the harness.

You are correct. I went to three yards yesterday. The one that actually had two cars told me it would be 20.00 if i pulled it. Once I got back to the counter he asked if that was all i needed, I told him yes. He sold it for 10. That was both connectors to the ECU.

Funny enough once I got the pins out, I noticed I had two of them sitting beside my desk from the weather pack connector I used for some stuff awhile back.

I got them installed last night, and the car wouldn't start. I'm about to reload my tune and try it again.

It's a good thing you didn't try stuffing the Weather Pack pins into the Miata connector - if you succeeded, you'd probably have broken the connector.