As far as the sensor signal, here are directions for testing it. However, it requires an OBD1 scan tool.
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TEST DESCRIPTION: Numbers below refer to circled numbers on the diagnostic chart.
1. Checks MAP sensor output voltage to the ECM. This voltage, without engine running, represents a barometer reading to the ECM.
2. Applying 34 kPa (10" Hg.) Vacuum to the MAP sensor should cause the voltage to be 1.2 - 2.3 volts less than the voltage at Step 1. Upon applying vacuum to the sensor, the change in voltage should be instantaneous. A slow voltage change indicates a faulty sensor.
3. Check vacuum hose to sensor for leaking or restriction. Be sure no other vacuum devices are connected tot he MAP hose.
Let me know if that helps. If you can provide the code or codes you found, I may have a specific diagnostic flow chart for it. Otherwise, this is what I have.
I hope it helps. Let me know.
Joe
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Thursday, September 3rd, 2020 AT 9:39 AM