Headcase0

The setup

MS3X assembled completely and wired for an LSX. It has a knock module, Mapdaddy 4, and a bluetooth module installed. I have rewired it for a Miata according to the trubokitty guide and various forum posts here. You can see a pic of each board below (Don't mind the schmoo on the board, I haven't had an opportunity to clean it yet). This is all being installed on a pre-OBDII 1995 car with stock everything other than maf delete (replaced with GM IAT) and wideband o2 sensor (AEM X-Series 30-0300).

Mainboard (make sure to click the link for all the images): https://imgur.com/a/ypQZ5VV

Daughter board: https://imgur.com/a/xr5v7RO

Expander board: https://imgur.com/a/k8mQXPW

For the harness, I have both prebuilt, 8' MS harnesses.
- Wiring diagram I used for the mainboard harness: https://www.diyautotune.com/wp-conte...-thumbnail.jpg
- Wiring diagram I used for the expander board harness: https://trubokitty.com/assets/images/ms3x_expander.png

I had to change up some of the wiring for the main board (namely the signal and chassis grounds) to match that of what the harness had outlined; however, all the inputs and outputs for the sensors remained the same as outlined in the trubokitty guide.

For the basetune, I'm using the 94-97 MS3X tune from trubokitty's website.

Problem

The ECU doesn't seem to be getting any sort of crank signal, preventing me from actually starting the car. Additionally, my fuel pump will constantly run in the on position regardless of what the priming pulse seems to tell it to do.

Attempted Fixes

1. 1k ohm pullup resistor between the white crank input wire and gray +5v wire
2. R12 and C30 mod as outlined in the main board imgur album
3. 1k ohm resistor on pins IG and B in the diagnostic box

Additional Notes

The car will fire and kind of idle on the stock ECU in its current configuration (albeit, extremely rich)
While in the MS testing mode, both the injectors and coil packs seem to work (there's a noticeable tick on each injector pulse and coil pack pulse)
When coming up to discrepancies between the MS wiring diagram and trubokitty diagram, I erred on the side of MS wiring diagram.
I have attached a log of what happens while cranking

Thank you for any and all help provided

ConnorRigby

Update to this thread. I am now looking at the ECU in question here. Ive confirmed that the MS3 cpu card, as well as the MS3X card both run while connected to my know working main board, with my known working patch harness loaded with my known working tune.

I've ensured that the tach select and vrin and vrout jumpers are all set correctly, as well as removed the bluetooth and knock modules for good luck.
I've also added the 1000 ohm pullup to tachselect as well as checked the pots and meticulously set them to the same values as reported by my trubokitty built mainboard. Any other pointers would be helpful.
current tune and composite log attached

EDIT:
Also something of interest that hasn't been mentioned yet, The fuel pump comes on with key on, but never turns back off. I'm tracing out right now to see if there are any unexpected mods to that circuit.

gooflophaze

R52 R56 trimpots been set to their initial turns?

ConnorRigby

Correct. R52 and r56 turned 12 times ccw, then r56 8.5 times cw. On ms3x I turned both pots 6 times ccw, then r11 back cw 3.5 times

ConnorRigby

Bump. anyone have any ideas?