problem getting my megasquirt running (wont start)
 

Having a little trouble with my megasquirt. i am using a megasquirt 1 with a 2.2 board. the car is a stock 97 1.8 manual (i bought the MS1 from diyautotune, i didnt build this board myself)

I built my harness to the specifications of this diagram:

http://boostedmiata.com/MS/9697_boomslang_harness.jpg

I referenced the diagram to the back of the connector (i believe this is correct?)
i wired it to the back of the female connector exactly as it is depicted in the diagram, with the injector wires (pins 34 and 35) wired individually to the G/W and Y locations on the connector(same with pins 32 and 33, other injectors)

i believe i did the wiring right, but i am second guessing myself.


I followed braineack's guide to setting up the software, updated my firmware, changed the custom file, adjusted the configurator, etc. and used a 96-97 basemap i found on diyautotune. the only things i really know how to do (or rather, am confident in doing so far) are mess with the trigger angle in the guide and "open" a basemap (not entirely sure if this actually flashes the megasquirt or not)

Anywho, i went to crank the car and it appears that the fuel pump turns on in megatune, but the car does not crank.

Any help would be very greatly appreciated, this is my first attempt at ever tuning a car

When you put the key in the ignition and turn it just shy of where it would usually turn over the engine what happens? Any lights, noises ect. happening?

What I'm playing at is a possible dead battery. If that's not the case I'd check to make sure all the wires are where they are supposed to be.

im sorry i used the wrong wording, the car will "crank" as in the starter will turn, but the car never actually starts and runs.

the harness diagram still has me a little confused, does it matter whether it is pin 34 or 35 that goes to G/W or Y on the diagram?

I have no idea, I haven't even built a MS, I was kinda baning on a dead battery or something like that.

me too! :) i appreciate the help though

With the key in the 'ON' position, what do CLT and IAT show? They should read roughly ambient temp. If you wired it backwards, they will have funky readings.

IIRC, the 90-93 diagram is mirrored (i.e. staring AT the connector from the perspective of the ECU). If you look at this harness I built and compare it to the diagram, you can see that on the diagram, the switched +12v to the ECU is on the right side of one of the connectors, but on the harness, it is on the left side (red wire near the bottom left of the photo).

https://lh5.googleusercontent.com/-o...0/P2240109.JPG

https://www.miataturbo.net/attachmen...ine=1324346927


The car will crank because (and don't hold me to this, because its how my BMW is wired, but I can't guarantee a miata is the same way) the starter motor is fed unswitched 12v from the battery, and the solenoid is fed a keyed 12v to engage it.

odd, the way i wired mine the red wire in your picture would be the green/white clutch wire on the back of my connector according to the way i read the diagram.

if thats the case the diagram would make more sense to me if the connectors were switched left and right, and have the perspective as you said of staring AT the connector from the perspective of the ECU

Its been a while since I've built a harness for a miata, so before you take this as gospel, try what I suggested and check your MS for connectivity and IAT/CLT temps. if you read it backwards, the MS shouldn't even turn on as it wouldn't be getting power.

it also seemed odd that my "pulse width" on the megatune would fluctuate with the rhythm of the starter while i was trying to crank it

also, the MS will not turn on unless the car is being cranked, ive had to flash with the stim the entire time, would this also be a symptom?

Suggest that you use Tunerstudio instead of megatune. Easier to use and helps find out issues faster as well.
http://www.efianalytics.com/TunerStudio/

Also yes the MS should be on with the key in the on position ( atleast this is how it works in my car, wired in correctly )

ill look into tunerstudio, i saw a writeup for an install with it and it seemed pretty friendly.

judging by this ECU pinout diagram:

http://www.plxdevices.com/ECUDatabas..._MIA_96_97.pdf

i should be looking at the face of the connector and not the back when looking at the wiring, so it seems all of my wires are backwards and i get to solder them again! oh joy :)

Meh, live and learn :D.

im just happy that i figured out something wrong! lol

just rewired the harness and the rpms and such work correctly with the stimulator, and the MS turns on when i turn the key.

still wont start though, about to try tunerstudio ill report back with my findings

no luck, computer kept blue-screening so i called it a day. does anyone have a decent base tune to start with tunerstudio?

If you loaded a basemap from diyautotune just install tunerstudio and connect to the ecu and let it autodetect which firmware you have and pull in your settings.

did diyautotune mod the MS for a miata?

nay, I just ordered this:

http://www.diyautotune.com/catalog/m...unit-p-34.html

I did load the hr10g firmware onto the controller though.

I noticed that the injector wires soldered in this picture:

http://www.boostedmiata.com/MS/harness/harness011.jpg

were shared between 2 different pins, I corrected this tonight on my harness (each individual wire was on a different pin on the harness), but to no avail, the starter still turned, but the car did not start. I tried, just to make sure, to see if the car would start with everything stock, and it did.

I also tried tunerstudio, and every time i tried to flash a tune, it bluescreened (laptop is a POS).

hope I can figure this out, as im itching to drive again! Driving an F-150 at the moment, and it just doesnt feel right!

Any time you mess with the megasquirt, datalog!