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knock sensor

Discussion in 'Care & Maintenance' started by m4tt, Jul 8, 2010.

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    m4tt 2000 celica

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    knock sensor

    what does the knock sensor really do and how does it affect driving
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    RinconRolla98 Well-Known Member

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    It allows the engine to run with the ignition timing as far advanced as possible. The computer will continue to advance the timing until the knock sensor detects pinging. At that point the computer retards the ignition timing just enough for the pinging to stop.

    A knock sensor assures that you're getting as much power and fuel economy as is possible from your engine.




    knock sensor



    The knock sensor responds to spark knock caused by Pre-detonation of the Air/Fuel mixture. As the flame front moves out from the spark plug ignition point, pressure waves in the chamber crash into the piston or cylinder walls resulting in a sound known as a knock or ping. This is caused by using a fuel with a low octane rating, overheating, or over advanced timing. Sometimes it can be caused by hot carbon deposits on the piston or cylinder head that raise compression. A knock sensor is comprised of Piezoelectric materials; Crystals that when impacted, generate a voltage (same idea as a BBQ ignitor). This voltage is monitored by the computer, and when an irregularity is detected, the computer corrects timing in VVT (variable valve timing) engines, or triggers a DTC Diagnostic Trouble Code) in older vehicles.
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    m4tt 2000 celica

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    ok so my car is running as retarded timimg then? what happened was i had a 2000 1zzfe and i swapped it with a 2005 1zzfe. the sensors are completley different but i had to use the harness off my old motor
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    SaberJ2X Lurk MOAR

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    it should feel the same as before in power...

    worst case scenario your mpg takes a HUGE dive when a knock sensor is bad
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    m4tt 2000 celica

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    can a tuner fix it through the computer
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    SaberJ2X Lurk MOAR

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    no, he can disable it, but if you use bad gasoline or something happens in fuel delivery or yadda yadda, it will still run like normal but could fuck it up...
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    m4tt 2000 celica

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    today i dissected the wire harness and now i think i just got to take the time to rewire the sensor
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    SaberJ2X Lurk MOAR

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    much better alternative... your engine will like you

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