Hi Sammy,
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I have a question for you though, I have been told that grounding the lamda sensor wire will fool the FV to go rich also. Is that basically the same thing that the WOT switch is doing or will grounding the wire make it go even richer than at WOT?
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No, that's not true at WOT. It has only an effect at idle and at part throttle. Because of the simple fact that the WOT switch is specifically there to tell the Lambda brain to IGNORE the O2 sensor and go to it's default WOT rich setting. Grounding the O2 sensor at idle and part throttle simulates a lean mixture to the lambda brain and it goes to full rich on the FV (90% duty cycle or so). This is typically way to rich for idle and part throttle and just causes the usual too rich running problems. At WOT the lambda brain defaults to something around 60% duty cycle. That means there's actually still quite a lot of enrichment capability left. By leaving the Lambda brain in closed loop and using the LM-1/LC-1 to 'fool' it to regulate to a desired WOT AFR, as described in some previous posts, you can make use of that capability AND hold the desired WOT AFR.
A quick and dirty way (without AFR control) is to disconnect the WOT switch from the Lambda brain (so it stays in closed loop) and then instead use the WOT switch to ground the O2 sensor. THAT will cause it to go full rich at WOT only, but then you might be too rich before boost comes on and you might have rich bogs when going to WOT from low rpm.
Whenever you disconnect the WOT switch, disconnect it at the switch itself ONLY, not at the Lambda brain. The 15degC switch is wired in parallel to the WOT switch and grounds the WOT-input to the Lambda brain when the engine is cold. This causes the Lambda brain also to go to it's default WOT setting (and ignores the O2 sensor). You want to retain than function.
Regards,
Klaus