Where did you mount the lambda sensor?? just after the extractors/collectors come together is a good place. I've also got the innovate wideband, but the portable handheld, not the dash mount one, and I've had it in many carb fed cars, plus my own turbo drag car. The signal tends to bounce around if you have an airleak in your exhaust ahead of the sensor or if your sensor is not at optimum temp. (is your heater wired in and working?) If you mount in the tailpipe end, it also bounces around at low rpm due to reversion back into the exhaust between pulses of gas