Is this a noisy or normal signal?
 

I'm a bit worried. My gauge will only go to 21.5 full lean instead of 21.9, and last time this happened my o2 signal was ridiculous. This is not as bad, but the frequency is way faster.

Am I just being paranoid?

I'm assuming it may just be a gauge problem, this log shows 21.9

Looks very noisy imo. Check/add grounds to everything until you fix it.

One good way to check for noise is to add max delay to the sensor and then see what the ouput looks like.

looks like noise to me, do you have it grounded to the same place as your megasquirt?

Its grounded to the same place as the MS. I havn't touched anything. This always seems to happen after 5-6 months. The signal goes noisy without me touching anything at all.

Solution: buy a UEGO instead of lc-1, win. Thats what I had to do to keep my sanity.

I constantly throw this idea around. The lack of reliability of this thing is driving me up a wall.

Tell us exactly how it's wired-up. Specifically, where is the gnd for the computer, the gnd for the WB heater, gnd for the wideband sensor, and anything else notable.

I've installed/fixed 6 LC-1s and never had a problem.

It's funny you mention this. I started with a UEGO and switched to an LC1 after a lot of frustration with offset of the analog output.

Wideband systems are finnicky, and they're just barely mainstream tech at this point. Folks have had problems and success stories with pretty much every unit out there.

All the grounds are spliced into one ground. That ground is then spliced into the ground at the MS harness. black/green wire I believe.

power comes from the radio.

its generally not a good idea to share power/analog and signal/digital grounds.

btw, I have an MTX-L and have zero ground problems (my ground is at the dash).

plus splitting the grounds up is generally better anyways, although not likely to matter in many cases.

I would add some more grounds first, but if that fails find a better power source that isn't shared.

The LC-1 has a built-in smoothing function, BTW. You may need to play with that a bit.

whut

Details? I've never even heard of this.

Yeah seperate piwer and signak ground

Out of curiosity where do you guys get your power from, and where do you put your grounds? Not in much of a mood to experiment, I want to make this work the first time (or in this case like the 5th time).

Any ole key-switched white wire with red stripe

Spliced power from the radio ignition wire (I think it was blue and black for me, blue and red was constant 12v).

I ground it on the support brace for the center dash. I pretty much crimpped the dimming wire with the ground and bolted it to the brace.

I think you have two separate grounds right? If they are coming out of the sensor, you should look for something in that area, but away from the exhaust. if your grounds are coming out of the gauge (like mine), I would find a decent area under the dash. glove box area has a few bolts you can use too.

just make sure you clean any paint off from under the bolt/crimp.

Splice/plug into power window connector (near shifter), plenty of current there... and if you don't have power windows you can actually just plug into the connector with crimp connectors. Use the ground there for power ground. I've done a couple cars this way with LC1 and 14 point 7 WB. Both cars are winning to this day. (make sure the signal ground is run to the sensor ground close to the ECU)

Look at section 6.5.1 ("Advanced Output Programming") of the LC-1 Manual on pages 14 and 15. You can setup the analog output to either be instantaneous or have up to 1/3 second of smoothing. This might help your noise.

Condensed into one post

Gave it straight battery power. 12v.

The ground wire when its not grounded says 9.5v.

Does this seem wrong to anyone else? With no ground, shouldn't I be seeing 12v at the ground wire? I have a feeling one of my wires is rubbing against ground or something...

Sorry, perhaps my advice is misplaced.

Did you try grounding it to the engine block, or close to an engine ground wire?

Refer to post above to see why I have not done that yet.

I accidentally gave the LED 12v and blew it up lol. Anyway after yanking on some wires, my gauge reads the normal 21.8 when full lean (compared to the 21.4 it used to read full lean), but I just looked at the signal and it still looks kind of noisy. Actually, pretty much identical to what I posted in the OP. I'm about to ready to rip this out and start fresh.


So the instructions as everyone knows, say to ground all the wires to the same ground point. You guys are talking about grounding the heater and signal to different places. What wires are these and why should I not be following what the instructions say when every thread I've searched says to follow the instructions? The blue and the white wire along with the black wire from the gauge are grounded at the ECU ground wire, all together. I'm getting power for the gauge and the LC1 from blue/black wire that powers the radio.

What am I missing here?

On top of that, trying to find the power window 12v source for the LC1 only made me realize that....my car does not have it. The connector that I expected to find is gone. I can't even find the damn wires. Does anyone know with certainty what colors these wires are on a '92?

By adding a ground, do you guys mean just running an extra wire from those 3 ground wires to somewhere on the chassis?

adding a ground would mean running a ground wire from the engine to a new location on the chassis. In this case the suggestion would be to put the ground close to the LC1 ground (or better yet crimp/solder a long ground to the engine).

I am pretty sure you don't need that calibration circuit, depending on the AFR gauge you are using.

I have to say I am glad I got an MTX-L, ---- was easy.

The MS1 has separate power and sensor grounds? Where are they grounded?

Here's what I might do.

All power grounds to a given lug on the engine block or head. MS, and LC1 blue wire both.

All signal grounds to a 2nd lug on the engine block or head. MS, and LC1 white wire both.

When I had noise issues on my aem wbo2 I just ran a new ground from the gauge to the stock grounding point on the engine and that cleared it right up.

Uhhm, My MS1 is grounded wherever the stock ECU is grounded.

Just to clarify, you're saying LC1 blue wire and LC1 white wire to the block on 2 seperate lugs? Even though it's a 6 wire (not sure if that changes anything)?

And which MS wires are you referring to, right now both the blue and white wire are on one of the MS ground wires, and I don't know where exactly that ground wire goes. Nor do I know which one is a sensor ground or power ground.

What I was going to do was run an extra wire to the block from where my MS ground, LC1 blue and LC1 white wire meet.

I'm too damn busy to work on this car, as you can tell from my delayed responses. :vash:

I'm also finding this out. Its WAY off on HPTuners. Can't you adjust the offset with the Innovative products but not the AEM unit?

Well, a select few of them do.

I suspect perhaps he was speaking of the LC-1, however. It has separate grounds for the heater and the logic/analog section, and while Innovate suggests that they be grounded in common, I suspect that grounding the heater separately and the analog/logic section to the ECU (as near to the ECU itself as possible) would be cleaner.


No. The AEM UEGO does not allow fine-calibration of the analog output. This is one reason why I vastly prefer the Innovate product.