Question about discrepancy between AFR gauge and MSPNP reading
 

Been having this issue for quite some time but just decided to ignore it for the most part.

I have an LC-1 and MSPnP gen 1. LC-1 output 2 goes into MS and output 1 goes to a stand alone gauge.

The issue i am having is that MS is always about .5-.7 leaner than what the stand alone gauge is showing.

I checked all the setting and they are just what DIYAutotune recommends.

LC-1 is setup for 0 volts = 0.500 lambda and 5 volts = 1.523

MS setting are: Configuration setting set to Innovate LC-1 default, 0-5v= 0.5-1.5 Lambda

EGO Control is set to Wideband and switch point set to 2.45 Volts.

Any ideas what could be causing this discrepancy? Which reading is the correct reading?

Where exactly is the LC-1 grounded?

The actual lc-1 controller is grounded at the head where there a a ton of other grounds.

Where is the ECU ground on 1.6l?

called innovate today. And had a pretty bad customer service experience. The guy right at the start was condescending and would not listen to me kept interrupting me. Only thing i got from him is that i need to match the input of MS to the output of the LC-1. He did not tell me how to do it and i really did not feel like asking him any more questions.

I know there is a way to change the output on the lc-1 with LM programmer. But is there a way to change input in the MS? I am pretty sure my MS reads about .5 leaner than what the gauge is actually showing.

The ECU ground and the LC-1 ground need to be one and the same. Ensure that happens before doing anything else.

I would do that if I could find where ECU is grounded. Searched everywhere and can't find that.

I am working through similar problems myself. I think they are very understaffed at that company. Here's what I did, I went into the LC-1 controller (you will need to hook the laptop up with the supplied cables and 2.5mm pin (page 12 - 6.2 of the manual))Turn key on for power to LC-1. Go to the Info/Set AFR, type of fuel (gas 14.7). Then go to analog Out 1 and set to the defaults (0v=7.35 AFR and 5v=22.39 AFR) You get a choice of Lambda and AFR, click AFR. Do the same thing on Analog Out 2, this way the gauge and Megasquirt are seeing the same thing. Hit program to burn it to the LC-1. Now go back to each analog section and check that you got what you want. Now you can get out of the LC-1 stuff, key off and hook up the MS cable. Key on, go to tuner studio, open your tune, go to -- Tools --(top of the page) -- scroll down to Calibrate AFR Table. Under EGO Sensor choose -- Custom Linear WB. That will allow you to input the volts and AFR points.
Point 1 .35v ----- 7.35 AFR
Point 2 5v ----- 22.39 AFR
Then hit write to controller. Your're done. Turn key off, wait a couple seconds, then turn on and start car and check to see if they are reading the same. If they are not, you will have to go back through the Calibrate AFR table again and adjust the .35v up or down and see what gets your individual car the closest. Oh, and each time you go back into Calibrate AFR Table for some reason it will look like no settings have changed. Revrant says that's the way it is when I asked him about it. So you go through everything again and make another little change till you get what you want. Anyway, thats what I did.
Cheers,
--JB

Wow dude! Thank you so much for this! Will try this tomorrow morning and report back! Thank you again!

Unfortunately I don't even have afr table calibration in tuner studio as an option:-(

That's OK, you might still be able to do this by adjusting Analog 2, which is the input going to Megasquirt. For example instead of 0v, try .35 and see if it gets you closer together. Keep notes so you can go back to what you had before.
Let us know how this works out.

Dude, check your ground points first! Getting that right will make your life easier. Its at location #2 in Brain's post #9 here : https://www.miataturbo.net/general-m...ocation-19644/

Same as second pic in first post here
Location of engine grounding points - MX-5 Miata Forum
Has one black and one black w/ green stripe wire bolted down on it.

EDIT: dont move any original stuff, just put a new lug with all ground wires soldered to it on top of existing stuff with a new nut on the stud. Also, you could run your ground wires into the MS ground close to the ecu body itself instead.

I know for sure that my controller is grounded to the right place. Not sure on the gauge itself tho.

I'd route them to the same place. That way there is the least amount of discrepancy between the controller's readout and gauge's value.

Fixed the issue. it might not be the right way to do it but it works. I used log works to get the reading directly from the controller and it was the same reading I get in the mspnp. So it was the gauge that was off. So I just scaled the input for the gauge to show same reading as the logworks. Now the ms and the pillar gauge are almost dead on.