I've a question to the LC-1 experts here.

I've mounted the LC-1 yesterday.
I hooked the switched 12V to the same pin where the map switching harness is connected, and I bolted the ground to the reinforcement bar just above the ECU.

The sensor is working, but the signal is somehow oscillating between AFR 12.5 and 14 by constant driving. At stand the signal is either at 13 or 12.5.

Do I have a ground problem?

If yes can I solve it by tapping into the ground of the Map switching harness.

Thanks fro your replies

mlocatel

 

not sure if you can draw that much current through the +12/ground pins.

I would use the ciggy lighter as source and chassis as ground..

 

It's actually less than 1A.

The original sensors have the same setup for the heating circuits.

I moved the ground to the same ground as the harness. It seems more stable, but now I've an error in the calibration

Tomorrow I'll try again. If this doesn't solve it, I'll try what you suggested.

Thanks

mlocatel

 

How far back is the sensor located in the exhaust? It can't really react fast enough to changes in AFR if it's mounted back too far. It will probably always oscillate a little, but the farther back the sensor the more it will do it. I think mine moves around about 1 AFR or a little more on average, and it's mounted in about the location of the stock rear sensor.

Play with the settings on your LC1 to both get it oscillating less, and to run closer to 15:1. I set my two points in the LC1 to about .7:1 AFR apart, and the half way between them should be your average AFR. There is kind of a grounding offset or something between the ECU and the wideband usually, so that offsets it about .04, so you also have to make up for that in your settings or it will run a little richer than necessary.

 

Hi

it's mounted just after the bend of the DP.

I have a calibration error since probably there were still some exhaust gases in the exhaust as it was calibrated.

Tomorrow I'll do it after 1 night, so it should be ok.

The oscillations are on the Wideband USB input, and not the ECU input (still did not connect)

BR

mlocatel

 

You can just accelerate and then let off the throttle, then wait a couple seconds after it cuts fuel for deceleration and then recalibrate -- no need to wait overnight.

 

Or coast to a stop in gear with the car off in 3rd gear (obviously make sure there is no traffic around), or use a vacuum to suck out the exhaust fumes.

You know, if the signal is oscillating at cruise that is normal. That is the way a narrowband car is supposed to run. The fact that it is richer than normal could be related to your tune or calibration.

 

Ok

thanks for your help guys!

 

hello guys

I had a grounding problem after all. I connected the LC-1 ground to the ECU and now it's fine.

The only issue is now with evoscan, but anyway I want to connect the brown wire to the ECU for easier logging and reading (I have the GPS evoscan)

mlocatel

 

Are you also using the LC-1 as your front O2 sensor input to the ecu?

 

No

I'll just use it for tuning and checking purposes. I'm not sure the LC-1 is reliable enough to substitute the OEM sensor

BR

mlocatel