Innovate mtx-l data no longer in log

[Deuce]

Ideas please,

Fresh engine build (11comp 355", 248/252 camtech, VR SS) running 11p nvram for probably 6+ years now. Just started the new combo a few times and was hoping to fix leaks, work on idle tune, run-in, cruise tune, shift maps etc
Relocated mtx-l from ashtray slot in console to passenger side of dash. (Moved oil pressure down 1 in ashtray slot and added trans temp above)
Data log is only showing 7.6:1afr. On the few short startups this far. Started today and was getting good readings on the display which was promising but still 7.6 in the log.
Used a multimeter on the gauge output (yellow wire, unplugged from wire to ECU). Started the car, gauge was still in heating mode, and I soon actually got good AFR data on the data log. Then the engine stalled (I modified the tune based on it being too rich, but have possibly caused an issue which I will look at undoing)

So how was the log getting good data with the yellow wire unplugged? And why does it get nothing with it plugged in? This doesn't make any sense.

[antus]

From the manual:

Optionally, the YELLOW (Analog out 1) and/or BROWN (Analog out 2)
can be connected to the analog inputs of other devices such as data
loggers or ECUs. If either one or both of these wires are not being used
isolate and tape the wire(s) out of the way. The default analog outputs
are as follows: Analog output one (yellow) is 0V = 7.35 AFR and 5V =
22.39 AFR. Analog output two (brown) is 1.1V = 14 AFR and .1V = 15
AFR. "

0V on yellow is 7.35 which is pretty close to 7.6. So might be a bad connection/bad ground and PCM is seeing 0v or something very close too it. How it got good data without it? Doesn't seem possible. It sounds like a wiring problem on the circuit, maybe the PCM input is connected somewhere else than the wideband?

[Charlescrown]

I just looked at a log I did with no wideband input and it is fixed 0n 7.3 so I agree with Antus there is no input from your wideband.

[Deuce]

Just to confirm, the wideband has been giving good data for years. And as recently as early March before engine out/in job with semi trans rebuild and exhaust mods etc.

The only difference is the location of the wideband, and that I no longer run the wire for lighting/dimmer which previously was only the ciggy lighter power and wasn't changing brightness of the mtx-l (so removed wire).
Maybe redoing that will fix data stream, but then also, it doesn't explain data on the log when the ECU input wasn't connected.

My nephew (20) was on the multimeter when it populated data. And said with one prob on the yellow output 1: 5v when ground to black wire, 0.1v when on chassis.
Which again doesn't make sense, as there is zero resistance between the black wire and any good point on the chassis.
And also, the car didn't run long enough for the mtx-l to display readings yet, so rightly shouldn't have output voltage down the yellow wire.
But then why did the data log show proper AFR's?
Could it be an ADX/XDF issue?
Although they haven't changed in 6+ yrs either.

[antus]

The wideband heater circuit switches on and off really quickly to maintain the right temp and creates a lot of electrical noise. Where you have the power and ground wires makes a lot of difference for interference. It is possible removing the lighting/dimmer made a change to the path of the heater power, and might have caused other electrical problems. You want the heater ground connected to a solid ground, and you want heater power going to some thick wire, closer to the battery the better. I wouldnt have expected the signal to go through the multimeter, but maybe it did, and maybe the resistance in the multimeter helped with interference. RFI is a bit like black magic. Its hard to explain, and hard to see. I'd just check and re-do your power and signal wires for the wideband and put the heater power as I described, and re-check the yellow signal wire connections.

[Charlescrown]

I gather your using TunerPro. I got the 7.3 when logging with the input to the ECU disconnected from the Innovate unit. It was fixed for the entire log so I figure it's a fixed value in TunerPro.

[antus]

I think the MTX-L gives a start up sequence when keying on, so if you are logging when power comes in to the car you should see two flag lines of 2 static voltages for a moment before it starts returning real data. if you dont see that the device is dead or there is a wiring problem.

[Deuce]

I gather your using TunerPro. I got the 7.3 when logging with the input to the ECU disconnected from the Innovate unit. It was fixed for the entire log so I figure it's a fixed value in TunerPro.

Yes I am using tunerpro.
Yeah, as shown above 0v output is perceived as 7.35:1 AFR.
(5v is 22.9:1 AFR)

[Deuce]

I think the MTX-L gives a start up sequence when keying on, so if you are logging when power comes in to the car you should see two flat lines of 2 static voltages for a moment before it starts returning real data. if you dont see that the device is dead or there is a wiring problem.

Interesting. I might try something based on that info tomorrow.
I've just unplugged the wiring from the ECU and checked that wire for continuity and correct socket engagement to the plug.
I've reattached the lighting/dimmer wire to the ciggy lighter illumination ring in case that had anything to do with it.
I checked the earth wire for voltage drop to the battery and there wasn't any drop.

Also, possibly unrelated, my ciggy lighter won't power my inverter (to charge the laptop) for more than about 3-5seconds. Yet the inverter will charge the laptop fine from the ciggy lighter in my wife's car.

[antus]

I read that as a massive red flag for power on that circuit