This is a recent problem - everything was fine until a few weeks ago (and the LC-1 has been installed since winter)

I've tapped power here:


With the LC-1's power unplugged, everything seems ok (although I haven't started the car to avoid damaging the sensor)

When it is plugged in and I put the key in the "On" position (car is off) the ISC buzzes crazily and my tach flutters between 0-250rpm. PFC Reads the same 0-250rpm flutter and the diagnostic port picks it up too... despite the fact that the engine isn't moving and I'm not trying to crank it. It only happens with the LC-1 plugged in

Anyone have an idea why it might be causing such an issue? Not sure if I should be tapping power from elsewhere or digging deeper to see what's up

Help please

 

Pull that wire out of its current power source and touch it to a constant power source. You could run a long jumper wire to the battery for example. See if that changes anything.

 

Good call
Used a direct lead off the battery and the problem still persisted, so it's not an issue with drawing power from that source
Guess I'll need to check the grounds now?

 

This problem probably because the LC-1 uses a switch mode converter to drive the sensor heater.

You are most likely coupling noise back into your engines crank trigger pickup. You should be able to fix it with stronger earths. What you probably won't be able to change is the sensor controller bricking itself WITHIN a couple of weeks of continuous daily use. You might get longer if you don't drive your car or it sits for long periods.

I would suggest you test it working on a bench and then sell it before it ***** itself and get something with a chance of lasting out your tune.

 

Thanks for the input
Sometime this week I should have the opportunity to have take a look at the rest of the wiring. The car rarely gets driven anyway, so I'm not putting a ton of wear and tear on the sensor (or sensor controller)
This is the first I've heard of the controller being prone to failure under regular usage. Is that a known problem for the LC-1? The sensor is far from the turbos and the controller is housed inside the cabin of the car, for what it's worth.
That said, I wouldn't sell something that I think only has a brief life remaining

 

The LC1 isn't the most dependable wideband. When it came out, it was one of the only options out there with its set of features. For what it's worth, I have had mine for over 3 years and the controller has been fine although it has burned out a few sensors. But I hardly drive my car--it's seen maybe 10,000 miles in that time. These days it's not the first wideband I recommend to people.

Can you explain exactly how you have your grounds run? The LC1 is finicky. There are three different ground wires--blue, white, green. I like to put the blue wire (heater ground) to a different location than the white and green wires (system ground and analog output ground wires). What gauge are you using? Is it the XD-16 or the DB gauge (red or blue display)?

 

I don't recall exactly how the grounds are run - I'll have to check it and let you know. However, I did use one of the diagrams on here as a guide during installation.
I'm not using any gauge with it... I run it into the datalogit/laptop during logging and that's all.

 

Got the problem solved
Turned out that it was feedback due to a common ground with the ECU. My Datalogit is mounted to the back of the PFC, so I guess when I was installing the LC-1 I saw where the ECU was grounded and thought "That must be a good ground or they wouldn't have used it"
Anywho, I moved "chassis ground #2" to a different bolt and now everything runs great. No more tach bouncing and no more hard starting.
Thanks for the help

 

Please post up when it dies

 

Please have someone post when you die