Water Injection and Lambda Sensor

[Richard L]

Just in case pyaap doesn't post the conclusion to this thread, I have the a possible answer from him regarding the lambda problem:

It looks like we may have identified the source of the lean running problems I've been experiencing as I discussed with you last week. I had a RACELOGIC traction control system wired into the car and it involved using a multi-plug connector to connect the fuel injector wires from the ECU to the Racelogic module. It seems like this connector was introducing a resistance into the injector wires which was causing them to hold back on injector duration. This explains why the engine was being starved of fuel eventhough the injectors were running at 100% duty cycle. This also affected the lambda sensor voltages as the pre-cat sensor was registering voltages of between 1.7V and -0.5V!! Volvo specs stipulate a cycling between open and closed loop of between 0V and 0.9V. Removing the multiplug connector and soldering the injector wires directly together seems to have cured the problem. The car is now running a lot richer and the lambda readings are exactly what Volvo quote. I cannot be absolutely sure what the AFR is until I get the car on a rolling road but it is a lot better than it has been.

In any case, thanks for your advice and I will keep you posted on what I find after I get the rolling road results.