I have to apologize up front. I have a heck of a time using the search utility. Every time I do search, I get a bunch of choices that don't even come close to what I need. Maybe I'm not doing this right. But anyways here's my question. Why are the knock sensors different between the Z28 and RS. Ran across this on ROCKAUTO.com. Almost ordered the wrong part number, so I'm holding of for a reasonable explanation. Thanks.

 

What year?
RS is V6 I believe
Z28 is V8 which could be 305 or 350
So 3 different knock sensors

I'm answering without looking up so I could be in the left field
Cheers

 

Different engine's use different sensors. They are tuned to listen at different frequencies. That frequency is chosen based on the bore size typically.

GD

 

SbFormula - 91 Z28 305
GD - Sounds logical.
Is there a way to check them if there's no markings legible?

 

For 305
gm # 10456126 for TPI
gm # 10456287 for TBI
enjoy

 

Unfortunately there is no way I'm aware of without sophisticated testing equipment capable of generating specific frequencies and investigating the waveform produced by the sensor.

GD

 

Awesome. I checked the one I have and the resistance between center probe and body measures 8190 ohms. Don't know if it's the right one, TPI or TBI. No markings on it.

 

https://www.thirdgen.org/forums/tpi/...k-sensors.html

 

Thank you TP.

 

Ohm test doesn't tell you which frequency the sensor responds to. Only which type of computer it was designed for. They made both types in at least 3 frequencies.

GD