Megasquirt users thread to discuss all things Squirty

[WDE_BDY]

This was the pinning I put together for my V2 V3.57 with the DIY Autotune loom -
DB37 Plug
1 Earth - Air Temp
2 Earth - Coolant Temp
3 SPR1/CANH
4 SPR2/CANL
5 SPR3
6 SPR4
7 Wideband Signal Ground
8 Hall Sensor Braid
9 TPS Earth
10 blank
11 blank
12 blank
13 blank
14 Good Engine Earth
15 Good Engine Earth
16 Good Engine Earth
17 Good Engine Earth
18 Good Engine Earth
19 Good Engine Earth
20 Positive - Air Temp
21 Positive - Coolant Temp
22 TPS - Signal?
23 Wideband Sensor
24 PIP - Pin 1 EDIS
25 IAC 1A
26 TPS Sensor - 5V feed
27 IAC 1B
28 12V Feed - through 3W fuse
29 IAC 2A
30 PWM Idle Valve
31 IAC 2B
32 Injector Earth - Bank 1
33 Injector Earth - Bank 1
34 Injector Earth - Bank 2
35 Injector Earth - Bank 2
36 SAW - Pin 3 EDIS
37 Fuel Pump Relay - Pin 85 or 86??

Modded a bit to show my EDIS connections but may be of some help.

Callum

[shrike]

shrike: are you sure the ECU is feeding dash info other than a tacho output? From that era of engine, there should be a separate temp sensor for the dash, the alt light & other wiring simply passes thru and some of the interconnect goes the other direction (e.g. circuit opening relay, EFI #1 & #2 relays, etc.).

Anyway sharing sensors that are resistive (TPS, CLT, AIT) isn't advised and I'm pretty sure that a VR sensor (e.g. CAS/dizzi) would also be an epic failed if shared.

fwiw, I approached the problem in my RA65 from the other direction, I worked out which signals the chassis loom needed, then either passed the wiring thru from the engine bay fuse/relay box or got the ECU to generate it.

Factory ecu controls dash abs and a few otherthings im splicing into the power and ground to the factory ecu and disconnecting all the engine controls/sensors the water temp sensor for the dash is seperate to the ecu temp sensor so ill leave that one alone

So pretty much the ms3x will control the engine

also the dash tacho input I dont need to wire into with the ms3 i will do a write up when I do it just waiting on the car to be ready and the ms3 to arrive from the states

I have all the factory wiring exposed in my project car and its a c**t to seperate it

[thechuckster]

shrike: that sounds like a PITA. You'll have to get a tacho signal from the MS3 to the dash somehow - the factory ECU will be generating it from it's own internal control or is it coming from the ignitor?

[shrike]

Its coming from the igniter so I can leave it alone thankfully and yes it is a pita but oh well I spent the last week working out all the wiring and I should be able to run the 5v signal to the ignitor from the spark a ref on the ms3x or the other option is to use the tacho out but Ill see what works best in car

[oldcorollas]

I thought the 3-wire O2 sensors had a wire for pos and neg of the heater, and the sensor ground was on the body.
putting the neg of the 3wire into the shared ground for the sensors would contribute a couple of amps and possible cause issues?
I like putting high current grounds direct to a battery connection, just in case...

[knightrous]

Finally got around to making up a tacho booster circuit so the DIYPNP tach out feature could drive the AW11's stock tacho.



Reads a fraction high on the tacho. Limiter is 8500 and it holds it under 8600 when bouncing off the limiter, but the tacho shows near 9000rpm.

[nuk1ear]

Finally got around to making up a tacho booster circuit so the DIYPNP tach out feature could drive the AW11's stock tacho.



Reads a fraction high on the tacho. Limiter is 8500 and it holds it under 8600 when bouncing off the limiter, but the tacho shows near 9000rpm.

Do you know if this is similar to what the SW20 clusters require? People on MR20C said replace one of the resistors on the PCB for the tacho with a different value (cant remember). So i did it, and my tacho reads about 200rpm above my actual idle speed (reads 1100rpm when im at 900rpm). when revving you cant really tell tho so its fine there, but it makes my car look like its running a high idle. Was thinking of just making it back to stock and making the tacho booster. MS3/MSx tacho output is the same sigal as MSPNP right? and i think the AW11 and SW20 have the same tacho input signal?

[knightrous]

If your just running the standard ignition setup, you shouldn't need to do this as your dash tacho will be driven by the stock coil.
You only need to use the tacho booster if you switch to COP or Wasted Spark setups. The guys on MR2OC might be right with changing/adding a resistor to the tacho feed as to adjust it, but I've no experience with this. Stock tacho's are generally out by some extent, so I trust the MS over the stock tacho

[nuk1ear]

haha yeh i trust the MS too. I changed to COP, running great. But yeh, using the MS tacho output to the tacho i changed the resistor to another one (stock 48k to 15k i think i used or 12k), people using hydra nemisis and stuff like that have no issues, and they produce the same output signal as the MS so should be fine i think, i expect the tacho to be off, but not that much at idle, its silly haha.

[knightrous]

Try putting a potentiometer in there and adjust it till it's perfect, then put a dab of hot glue to hold it into position.

[caam]

WDE BDY and chuck thanks for the wiring help, all seems to check out thanks +rep to you two

Latest problem is
Went to check oporation of everything again and configure my TPS, plugged everything in and powered it up,
All the LEDS on the megasquirt blinked then went out, then nothing - I can't get a singnal through the computer either
Through tunerstudio I went to the COMM settings and went detect and it found the megasquirt but says that no firmware is installed therefore can't do anything?
Re-did the download/installer of the computer and this took around 15 minutes through their downloader program (which I re-downloaded to make sure I got the latest version)
Yet the computer still reads no firmware!

Any body got an idea?

[nuk1ear]

using windows right? Have you made sure you have the latest version of the USB com drivers for the MS unit? its in the manual (this is if you're using USB)

[thechuckster]

Caam: pull the ECU out of the car and attach to a sim - then try to connect with the laptop.

Also, check all the fuses feeding it. Plus, open the lid and make a visual inspection (torched bits or the daughter board come loose or insulated jumper wires rubbing or caught.

does the V3 board have bootloader jumper pins like the older boards? (will go to the msextra site and confirm)

[caam]

Yep windows XP and have the latest drivers and it was working fine sunday night when I checked CLT/IAT sensors and everything repsonded fine through the car.
Wiped the current firmware again and re-installed it, this time it worked through the stim however no RPM signal which obviously means no o2 signal aswell - i'm running VR and I know this can be hard to test through the stim.
Plugged it into the car and laptop, powered it up and once again wouldn't connect with the laptop, but this time all the LED's on the megasquirt blink continuously while it has power.
Pulled it out and check stim, same thing. No signal on the computer and LEDs blink continuously
Visial check shows nothing out of the ordinary

Yes the v3 board has bootloader jumpers on the daughtercard and they were connected while installing the fireware and removed afterwards

[thechuckster]

it does sound like something in the car wiring has borked it.

Is the fuel pump LED flashing along with the others or just staying on?