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Wayne 962 Wayne 962 is offline
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Originally Posted by DW SD View Post
3.2L Carrera, 964, 993 all drive tach signal from the ECU. It would be surprising that 959 does not.

Is there head temperature sensor? Maybe it thinks the engine is warmed up? Not sure that would explain the ICV valve opening at speed.

Is there a chance the ICV is wired backwards?
Three very good questions!

- I can check the wiring diagrams for the tach wiring, but I'm guessing that you may be right there, that the signal comes from the ECU. I'll check the wiring diagrams soon for that.

- I tested the temp sensors, they seem fine, but even if they were bad, then the car would run fine when it gets hot. So, I don't think it's the temp sensors

- The car was running perfectly fine previously, so I don't think the wires could have magically reversed themselves? Still, stranger things have happened in the past.

Old 11-28-2007, 01:18 PM
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