cracked knock sensor

[Neejay]

I was getting code 34 (knock sensor) and I pulled my KS and it was cracked. The wiring seemed to be ok, but I bought a used one from a member here and I just got it today and its also cracked.

Mine was cracked more at the top of the "O" and this replacement is cracked near the neck (bottom of the "O"). Does this make a difference?

I don't want to go through having to remove my intake manifold again, especially without a garage.

Mine (original):
http://img.photobucket.com/albums/v422/neejay/CIMG1036.jpg

Spare, just bought:
http://img.photobucket.com/albums/v422/neejay/CIMG1047.jpg
http://img.photobucket.com/albums/v422/neejay/CIMG1043.jpg
http://img.photobucket.com/albums/v422/neejay/CIMG1040.jpg

[EAT Motorsports]

you would probably just want to fnd one that isnt cracked if you dont want to do it again...

[UNISA JECS]

I see alot of them cracked and still work fine, you need to measure the resistance of teh knock sensor, do a search under my name and knock sensor and you'll find the info you need to remedy you ECU error code, most likely its probably not even te sensors fault but rather a short in the knock sensor signal line which is known to happen on S13 especially.

[Landers]

I heard that a knock sensor is a pretty delicate unit in itself. I would just replace it if i was you. just my .02

[UNISA JECS]

The smart thing to do would borrow unless you have one a volt/ohm meter and know some the specifications of what your working with (i.e. knock sesnor, and ECU pin terminal and its refference voltage) before buying new parts, thats just what I would do becasue im not made out of money...lol.....

I'll save my self the hastle and just link you what I think if you follow this steps will prove to be very helpful, atleast I hope so.

http://www.sr20forum.com/general-sr20/213046-knock-sensor-junk.html

Below is quoted from me "UNISA JECS"
Before doing any of teh below check the component itself by checking the resistance of teh knock sesnor, a good knock sensor reads 560 Mega Ohms thats 560,000,000 ohms
Now you can proceed!
Well I fixed my knock sensor error code problem.
After spending many hours actually days on this sh*t I finally fixed the problem and the ECU now gives me a code 55 ......
Heres are the diagnosis steps I performed:
1. Disconnect ECM harness connector from ECM.
2. Disconnect KS subharness connector from KS.
3. Check harness continuity between terminal (B) and ECM terminal (27).
Im my case continuity did exist (so good to go right? NOPE) im still getting a code 34 and my knock sesnor is good to go.
Next I pluged everything back together like it should be then:
Step:
1) With a DMM, one probe to ground other back probing pin 27 (Knock Sensor) with KOER and KOEO.
Results = 0.013v (no good) FSM states you should see aprox. 2.5v at idle and or KOEO.
2) I disconnect ECM harness connector from ECM and de-pin, pin 27 from harness connector alltogether.
3) I re-attach the ECM harness connector to the ECM with pin 27 detached from connector.
4) With my DMM I ground one probe and the other to pin 27 and I get 5v, so the ECU is good to go.
So next step:
1) Taking a jumper wire to pin 27 and reconnecting the original (white) KS wire to the jumper wire I instantly lose the 5v (so im thinking why what is causing this to happen (a short to ground etc etc)
2) I take the same jumper wire and disconnect the original (white) KS wire from it and get about 3ft of regular 16 gauge wire and run it directly to the knock sensor subharness terminal (B).
3) I take measurements back at the ECM with my DMM one probe to ground other to pin 27 and I get 2.5v (good to go finally
4) So now I clear the codes and start the car run it for a few seconds and shut it off.
5) Check codes for any errors and all is good (code 55 finally)
If some of you are wondering why I didn't get 5volts when I rewired, its becasue the KS itself is a 0.560M-Ohm resistor and it reduces the voltage down to approx. ~2.5v.
My code 34 was instantanious means I could clear the codes and get code 55, start the car for 1 second then turn it off and check teh codes and I have a code 34, thats becasue it basically had no voltage present of pin 27.
Some other things that still stump me is I still got continuity between pin 27 and the KS sub harness but why or where was the voltage going to im by no means an electrical expert but I wanna know where it was going, is that what a short to ground would do???

[UNISA JECS]

After you read that these other threads might help you out to:

http://www.zilvia.net/f/showthread.php?t=137317&highlight=knock+sensor

http://www.zilvia.net/f/showthread.php?t=137317&highlight=knock+sensor

[Anto]

PS

You don't have to take off your intake manifold to access the knock sensor.
I did mine using a 15* wobble extension, and I used a dab of grease on the head of the bolt to keep it stuck to the socket while manuvering it through the intake manifold runners.

[UNISA JECS]

PS

You don't have to take off your intake manifold to access the knock sensor.
I did mine using a 15* wobble extension, and I used a dab of grease on the head of the bolt to keep it stuck to the socket while manuvering it through the intake manifold runners.

Exactly what I did, and if your wobble is to wobbly wrap it with a few layers of electical tape to get the desired angle of degree.

[Neejay]

PS

You don't have to take off your intake manifold to access the knock sensor.
I did mine using a 15* wobble extension, and I used a dab of grease on the head of the bolt to keep it stuck to the socket while manuvering it through the intake manifold runners.hmm..thanks.

Exactly what I did, and if your wobble is to wobbly wrap it with a few layers of electical tape to get the desired angle of degree.Gotcha. Also thanks for that guide. I can check that if it comes down to it.

Also added pics in the first post.

[EAT Motorsports]

ah yeah pix sure help... ohm it out but it looks like junk to me...

[MURPHY]

i have a non cracked one. pm me

and you can get it off without removing intake manifold. and if you have tools, enough swivels etc you can get back on too.

[Neejay]

bah...this sucks. I guess I'll put it on tomorrow, and see what's what...

[Neejay]

The smart thing to do would borrow unless you have one a volt/ohm meter and know some the specifications of what your working with (i.e. knock sesnor, and ECU pin terminal and its refference voltage) before buying new parts, thats just what I would do becasue im not made out of money...lol.....

I'll save my self the hastle and just link you what I think if you follow this steps will prove to be very helpful, atleast I hope so.

http://www.sr20forum.com/general-sr20/213046-knock-sensor-junk.html
Ok, after following that guide + viewing that thread on sr20forum, I got 3.33v with the sensor disconnected and connected (ignition on, car off). I don't know how to de-pin the wire and I don't want to mess anything up.

Did you run the spare wire directly to the knock sensor plug or did you basically cut out the direct wire and splice the wire in between:

ECU -> orginal wire (cut + spliced) -> new wire -> original wire (cut + spliced + plug -> knock sensor subharness plug

OR

ECU -> orginal wire (cut + spliced) -> new wire -> pinned (or whatever, the ends that slide over pins) -> knock sensor subharness plug

hopefully that made sense.