Low RPM signal, no spark
 

Alright this is the first megasquirt I've ever done, ever. Total noob here. Not sure on anything I'm doing tuning wise so bear with me.

So I have a 1990 1.6L stock miata, trying to run a MS1 v2.2 that I built, tested with stim (works). Modded per diyautotune's Instructions Only thing not stock about it is the GM AIT I put in place of the AFM box, and wired into stock harness (AIT tested and works)

My problem is that I barely get any rpm signal when I'm cranking, no spark. I was getting absolutely 0 rpm before I jumped XG1 and XG2. After that I get around 1600 rpm the second I turn the key then it goes down to 300 then 200 rpm where it sits till I turn the key off and all the relays die.

I've scoured the internet for hours on this and the only advise I've found so far is should have bought a MS2.

Any help is greatly appreciated. Thanks guys

charge your battery?

sounds like you didnt do the cmk/cmp input mods correctly.


here's how i had done it:

https://www.miataturbo.net/megasquir...30/#post673322

Here's how I have the mods done.

.1uf cap from CPU pin 11 to gnd
1k resistor from X11 to CPU pin 11
470ohm resistor from x11 to scrandy hole above and to right of D9

Those are done exactly like your linked mods. Should I go ahead and mod the rest like you did or....?

you pullup for the crank input is on the wrong side of d9. Needs to be on the positive voltage side to provide the pull up for the signal.


https://www.miataturbo.net/attachmen...ine=1459788653

Moved the resistor leg to correct side of D9

Now I get no tac at all again. With and without XG1 and XG2 jumped

I'll post my .msq, hopefully the right file. I'm thinking something with ignition and decoder wheel settings

should be using 4G63

https://www.miataturbo.net/attachmen...ine=1459803435

Wrong firmware? Dont see an option anywhere for 4G63

sorry, forgot youre MS1. Been like over 10 years since I looked at that firmware.

that looks correct.

Ok, I was about the flash the hr_10g firmware, guess I won't.

Set up like this I get 0 tach signal, should I go ahead and do all the mods in that linked post? Jump D5, D8, put leds to coils and such? All I have done now are those on the backside of the board.

The two jumpers are needed for tach.

Alright I've jumped D5 and D8 as well as XG1 and XG2.

On tuner studio I'm getting 200-260 rpm cranking, getting fuel but still no spark.

Should I do the coil output and PWM mods shown in your example?

You don't have the spark outputs wired to your harness...

This is how I wired my harness


https://www.miataturbo.net/attachmen...ine=1459902555

but you don't have the LEDs connected to pins 31 and 36.


and yuk that's an awful diagram. At least wire pin 27 to 2O and then run a small jumper wire in the AFM connector.

I've made all the coil connections on the ms board and hooked up pin 27 to 2O on the harness. I also did the launch in mod for the heck of it.

I have my AIT plugged into the 1st and 6th slot on my AFM connector, which slots should I jumper?

I set spark output A and B to the correct outputs, not sure how to setup fan.

Edit: When I crank with this setup, the fans run as soon as I turn the key to on,

Got engine to start idled like shit, then smoke came out of my board so I shut it down. Still powers up, any thoughts? 24 gauge wire too small?

Also did the PWM idle mod afterwords with a TIP120 transistor from radio shack, not 100% for the settings on that.

https://www.miataturbo.net/attachmen...ine=1460038698

https://cimg1.ibsrv.net/gimg/www.mia...334f2ed56f.jpg

Edit: set up like this with idle set to pwm at 62% hertz car runs. Idles kind of high around 1600-1900. Working in it, making progress.

Edit: moved car, stalled out, wont start again.

I got the car to idle where it should at around 1100rpm for warmup by adjusting the idle valve dc, still oscillates a little. I think the cause of some of my problems are caused by my coolant temp staying at -40F at all times. Checked my harness, getting ~4.97 volts from the car, no difference cold or hot on the stock gague. And at one point the stock tach was working, now is not.