LC-2 installed on stock ecu, hesitates while warming up
 

Hi all

I got impatient waiting for Reverent to send me my MS3 so I went ahead and installed my Innovate LC-2 with the factory ecu. This will be only my first tuning experience and so I figure it would be good to see what that factory ECU does for reference. I have wired the LC-2 power into the radio circuit, one output to the gauge, the other output to the factory narrowband signal wire, and grounded everything to the ECU ground. I have the LC-2 set to the default narrowband output (approx 0.1 - 1V for 15:1 - 14:1).

Here's what happens. Cold start. It cranks, starts and idles just fine. I can pull it out of the garage with maybe 10% throttle, but when I get moving and try to give it any more than maybe 20% it stumbles and the wideband indicates lean (like, 16-18:1). Light throttle seems fine at around 14.5-15.3:1. It goes away after ~1-2 minutes of light driving and the car runs great. If I turn the car off and restart, it runs fine. Any ideas? Car ran just fine on the factory narrowband.

Are you sure you've run the narrowband sim wire out to the factory o2 input?


We need details on your car as well.

Sorry, stock 95 miata (intake to catback).
Yes I'm sure - I ran it to the red/blue wire in the factory O2 plug. The car wouldn't idle at all when I first hooked it in, because both outputs were set to wideband. Had to reprogram the one hooked up to the ECU to be narrowband. And it runs just fine after a couple minutes.

Ground the wideband to the ground under the throttle body.

Instructions state to ground with the ECU, and that's what I've read to do with many others. It seems like it must be some kind of warmup settings in the factory ecu that the wideband isn't compatible with. I was hoping to find a response from someone whos done something similar in the past.

The ground for the ECU is the ground under the throttle body.

Just in case someone finds this in the future, I fixed it by messing with the calibration. The default calibration from innovate had the car idling at around 15.1:1 so I moved the afr range a bit to get it to idle at ~14.6. Still a little lean during warm-up but maybe that's a part of the factory ecu scheme?