vacuum pressure switch

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wayne billings

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'86- with no history. Recently assembled garage find, 35 k miles. Vboost not working. I sent the controler to have it inspected and it came back with a clean bill. With everything connected, new battery and the key on, not running(it does run well). the voltage at the pressure sensor is 5 volts checked at the harness. the voltage at wires from the controller leading to the servo is 5+ volts ( round plug). Are these normal readings? I have not found this info on the forum yet. Thanks in advance. Wayne :cool:
 

RempageR1

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Vboost engages on the RPM pulse, it does not get it`s reading from the vacuum. That one is used for ignition advance. Does your Vboost server cycle to open and back to closed when you turn the key?
 

maleko89

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You can try applying/jumping power directly to the round Vboost plug and test the motor. If that test passes, it's the servo or harness issue.
 

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