| Douglas,
The 150mv is a 'base' setting with, as you say the butterfly fully closed. Once the TPS is set, then the throttle stop screw should be used to adjust the TPS value to 287mv (748 EU) this is the correct position for the ECU to use the look up values.
The tickover RPM may need adjusting but this should not involve changing the TPS value.
U2U if you need any more assistance
Pete | 
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