Megasquirt and 02 communication Help

[Nitro Nick]

Hey Guys, I just started up my turbo build for the first time. It has been a year and a half process that I have finally completed. Here's a idea of what I have and what i'm working with.

stock M20
MLS head gasket
42 lb injectors
Megasquirt2 from whodwho
innovative MTX-L wide band
VDO Oil temp and oil pressure guage
cx racing manifold
t3t4 turbo with internal wastegate
greddy BOV
ARP head studs

At first I started it up and it was idling quite nice but my battery was really shot so I shut it down until the next day. Side note I could not connect my labtop to tunerstudio but I knew there was a startup tune in the MS so I tired it anyways to check for leaks. Finally got the correct driver for the usb to serial adapter. New battery and I started it up which would be the second time. This time it did not want to idle like the previous day and I finally was able to see all the gauges working. I know the tune is not meant for every setup but I wanted to get a heat cycle done so i could re torque the head studs (I feel that is important).

I know I need to find someone who is good with tunerstudio and tuning but there is one big issue in my way currently.

The wideband does not show any readings on the gauge or in tuner studio. I tried unplugging it and re plugging it with no difference. I have wired it into the existing 02 port via an adapter that one of our forum members sells. I followed his exact instructions for wiring the gauge up and I'm nearly positive it is correct.

Are there any specific troubleshooting steps in regards to tunerstudio with the wideband.

After that I intend to work on the idle and timing and such so It can idle safely. Not planning on taking it on the road now since it is winter in CT. But its in a garage and I can fool around with it while it sits.

Goal is to get the a/f gauge working and get it idling right. I don't want to start it up a bunch if the timing and fuel and air is all off. I have put too much time into this to jeopardize the entire engine.

Any help is appreciated. Thanks!

[nando]

your particular O2 sensor/controller has to be setup in TunerPro. It's not going to read correctly until you get that working. I wouldn't even drive it because any O2 feedback relies on the wideband calibration being correct.

[Nitro Nick]

your particular O2 sensor/controller has to be setup in TunerPro. It's not going to read correctly until you get that working. I wouldn't even drive it because any O2 feedback relies on the wideband calibration being correct.

I assumed that driving it was out of the question. Its honestly still on the jack stands now. But I was looking for kind of the steps in tuner studio to recognize the sensor. I need one of those tuner studio for dummy classes or something. But i know most of the tuning will be done by someone else until I get the feel for it. I am just trying to get everything recognized and working before moving forward.

Again any help is appreciated.

[nando]

I'm pretty sure it's covered in the msextra manual. http://www.msextra.com/manuals/

basically you just need to know what wideband controller you are using, and either choose it from the drop down menu or enter the voltage/O2 curve manually.

[Nitro Nick]

Havent been able to get over to the shop and test it out but one of my friends gave me some troubleshooting tips. Going to try them out tomorrow. If that works then I need to work on the idle.

[Nitro Nick]

Does anyone happen to know what the 4 wires that are on the harness side of the 02 sensor plug. There are 4 wires:
Black
Brown
yellow
Green with blue stripe.

Thanks

[ak-]

The black one is your 02 signal wire.
I connected my BROWN (Analog 2) wire coming from the CONTROLLER & WHITE wire coming from the AFR GAUGE to it.

Connect that one, and then connect your other 3 ground wires to the same ground on your shock tower (ECU ground).
Connect your 12v switched wire to something in the car.

If this setup/troubleshooting WORKS, your wideband doesn't like your harness - which I hope isn't the case since you bought a neat item.

(This is how I have mine setup btw - m20 turbo megasquirt LC-1)

[Nitro Nick]

The black one is your 02 signal wire.
I connected my BROWN (Analog 2) wire coming from the CONTROLLER & WHITE wire coming from the AFR GAUGE to it.

Connect that one, and then connect your other 3 ground wires to the same ground on your shock tower (ECU ground).
Connect your 12v switched wire to something in the car.

If this setup/troubleshooting WORKS, your wideband doesn't like your harness - which I hope isn't the case since you bought a neat item.

(This is how I have mine setup btw - m20 turbo megasquirt LC-1)

I purchased a connector that will allow me to wire the gauge to the existing 02 sensor port using an old plug and everything. The issue is that with the MTXL there is no separate controller. I think I have everything right except the connections at the sensor. Do you happen to know what the yellow and the green with blue stripe wires are for?

[Nitro Nick]

The black one is your 02 signal wire.
I connected my BROWN (Analog 2) wire coming from the CONTROLLER & WHITE wire coming from the AFR GAUGE to it.

Connect that one, and then connect your other 3 ground wires to the same ground on your shock tower (ECU ground).
Connect your 12v switched wire to something in the car.

If this setup/troubleshooting WORKS, your wideband doesn't like your harness - which I hope isn't the case since you bought a neat item.

(This is how I have mine setup btw - m20 turbo megasquirt LC-1)

Also I understand where you are coming from but the LC1 is different from the MTXL since the controller is built into the gauge and has different wires. I bet I could set up a similar setup though.

[ak-]

Google the MTXL and a pdf file should show up explaining the wiring

[Nitro Nick]

Google the MTXL and a pdf file should show up explaining the wiring

I got a few ideas. Its currently dumping snow in CT so I'll run some tests tomorrow. Thanks for the help!

[Nitro Nick]

Found out the problem. One of the wires was crossed when I wired it to the existing 02 port found the one that was wrong and it works great. The only con, (thanks to whodwho identifying it) is that when you use this existing 02 plug the power source is the same as the fuel pump. And when you turn the car to the on position it will only operate if the fuel pump is running. Therefor once the fuel pump is primed it shuts off and so does the 02 sensor and gauge. FWIW. He said you can use a different power source but this isnt that big of a deal.

[nando]

you can change the o2 sensor relay to trigger with the main relay. pretty easy really.

[Nitro Nick]

you can change the o2 sensor relay to trigger with the main relay. pretty easy really.

Do you know the steps?

[CorvallisBMW]

sub'd for future reference