1990 MSPNP AFR confusion?!
 

Hey confusedmx5 NOOB here. I've got a 1990 miata with a '96 1.8 swap. I have owned it for a year and just started modding it. I put a full exhaust, pod filter, and megasquirt to start off. Deleted the MAF, added the IAT, and switched to a AEM wideband O2 sensor with gauge. Everything has gone pretty smooth until today.... :/ I got it cranked with the first turn of the key, and noticed that the AFR gauge was reading fine. But the tuner studio gauge wasn't registering at all. The needle sits far left and the numbers match the needle at all times. I have checked the wiring from the O2 to the gauge, and the gauge to megasquirt. So I am stumped as to why it wont read at all? every connection is tight, secure, and mint. I even went so far as to get ahold of DIY and checked the wires were the right ones. I.E. red=+12v, black ground to block at ecu grounding, blue ignored, white ran to pin 21 of options plug. with the original O2 wire being taped off and secured. So any help would be greatly appreciated as I am officially stumped as to why tunerstudio wont register any afr at all.

What number you mean by "the numbers match the needle at all times"?

Did you calibrate in tunerstudio for your AEM wideband?
You sure no wires got pinched anywhere in your routing?

Sorry, so on tunerstudio the gauge "dashboard" has all the circle gauges. and the afr gauge has two sets of numbers the needle arch and then at the bottom has a stationary set of afr numbers that match the needle arc. neither one of them moves ever as if its stuck in NB still.

the calibration numbers I used came straight out of the AEM manual that came with the wideband. it is the new 4.9 version if that matters.

and I went so far as to actually unscrew the megasquirt, have all the wires pulled from everywhere and just layed out and even super straight they failed to engaged.

other info just for ***** and giggles. when I open the page under fuel settings at the very bottom, the little indicator peg moves with the fuel, also fuel pressure is being measured, fuel load, etc. its literally only the gauge on the "dashboard" so idk to be worried or not.

https://www.miataturbo.net/attachmen...ine=1459553128<br >Here is where I set it up, and what the gauge looks like at all timeshttps://www.miataturbo.net/attachmen...ine=1459553071<br >

I also broke out my multimeter and checked the output voltage and its a little off. At idle its reading .73 and not zero. Full throttle pushes around 3.43 sometimes 4 volts. But never zero or 5 for their respective ends of the range.

Most 5v signals operate somewhere between 0.5-4.5v, a 0v or 5v signal implies there is an open or a short.
My wideband configuration is a little different from what i remember.
Check your grounds and try the AEM preset calibration in the calibration drop-down list

I tryed the two preset AEM settings. But neither of them are for the newer 30-4110 sensor and also never read. But they did chage where the Ts gauge was sitting, but didn't give a reading. The only thing left is to check my ground wiring again, clean the ground, reattach it....hopefully that works but I won't know till I get off work tonight.

Alright, sorry for the long delay. I sold the AEM wideband. I also got a innovative MTX L and I followed the instructions for the wires all around. Went thought megasquirt and set it up. Started the car and surprise surprise. The afr gauge works perfectly.....but again tunerstudio doesn't show any afr at all. I rechecked all my wires and connections, I even tryed using the custom option and changing the volts per afr and still got nothing to change at all. I'm borderline ready to light this bitch on fire and take the insurance claim for it lol. Please anyone with experiance with this issues guide me a little bit. Thanks.

Can you post your MSQ?

@Matt sorry I've spent the last two days undoing the entire wiring harness from the ecu though the firewall and dash and into the engine bay. The last owner "wired" in a denso tps and some random bits of wire and tape to make it "connect". So I ripped ot all out and ran one solid wire from the yellow wire all the way back to the 2N pin of the ecu. And after futher studies found out 2M is for tps.....well that's not wired at all its tied into 2O lol. So yea I have my hand full of wire bits. But thank you all so much for all of your help and assistance with all this and for dealing with me lol.