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josh_adnoh
05-19-2009, 08:56 PM
ok first off all i did my research but i don't understand....i am new to this stuff so trying to figure this out....its been like a year that i got my s14 ka...and i started noticing these symptom's:

v-tec effect
loosing to an integra(aka: poor performance:p
bad gas mileage
misfiring

so i finally find out that it was my knock sensor i pulled my intake mani out of the way to get to it...now i have it in my hands

now i want to know if its my knock sensor that is bad or my wiring??
cause i know that allot of times its just a short or bad ground in the wiring??

there are little crack on the knock sensor but i read that doesn't mean there bad so i did a ohm test and this what came up
http://i300.photobucket.com/albums/nn13/josh_adnoh/Picture184.jpg
here is the fucked up sub harness is it suppose to be like that??
http://i300.photobucket.com/albums/nn13/josh_adnoh/Picture182.jpg
here is the other end that goes in the knock sensor
http://i300.photobucket.com/albums/nn13/josh_adnoh/Picture183.jpg
hopefully some one will help me and help others in the future

so
1: did i do the ohm test right
2:is it reading that i have a good or bad KS
3:is the sub harness suppose to be like that

I build motors all day
05-19-2009, 08:59 PM
knock sensor sub harness goes from two wire to one at the end of the knck sensor.

I build motors all day
05-19-2009, 09:00 PM
The factory spec is 500 - 620 Kohms.

I build motors all day
05-19-2009, 09:02 PM
how sure are your knock sensor is bad if there is no DTC's from the ecu. and just test the harness for continuity

josh_adnoh
05-19-2009, 09:05 PM
sorry it was throwing the code 34 wich is knock sensor...and ill try the harness

josh_adnoh
05-19-2009, 09:15 PM
no the black wire isn't touching the yellow one cause you see at the pic of the sub-Harness where it connects it just hanging there...so your saying that the black one i suppose to touch the yellow one right???

96Turbo
05-20-2009, 01:35 PM
the reason there are 2 wires going into 1 is because it's a shielded wire. the outter wire wrapped around the inside is a ground wire...it's supposed to be like that

however, i'm having the same problem with my KS system (code 34). I plan on checking:

resistance of the sensors (like you've already done & compare to the value listed in the FSM)

checking the KS harness for continuity (from ECU to sensor...this is where i think my problem lies)

good luck and let me know what you do to fix it!

Killa_D
05-20-2009, 01:40 PM
just go and buy a new subharness and sensor and call it a day.

96Turbo
05-20-2009, 01:54 PM
^^why do that when you can fix the harness for free and we've already concluded his sensor is good??

blackej7
05-20-2009, 03:30 PM
Actually, my knock sensor ohm'd out within spec, the wiring was good, and i would still intermittently throw a code 34.

I replaced the knock sensor and the code hasn't come back. Sensors do go bad eventually.

josh_adnoh
05-20-2009, 07:54 PM
got another used but better condition KS with sub harness and i think i know what was wrong....you guys know the ground the closest to the fire wall on the driver side of the engine,its in the same harness as the front o2...well that ground wasn't grounded,it was just haging at the back of my motor?
http://i246.photobucket.com/albums/gg87/psychokid259/ground.jpg

RPSil13
05-21-2009, 09:09 AM
can someone show me where the know sensor is located
thanks

Nezahualcoyotl
05-21-2009, 09:27 AM
lol its tucked under the intake manifold...
not my motor

http://www.brandonwoods.net/240sx/images/engine/knock_sensor.jpg

96Turbo
05-21-2009, 10:39 AM
nice lookin engine bay man. Is that a datsun or somethin? pretty cramped in there :bigok:...........loooks like my RB in the 240...

Do you have some pusher radiator fans? or are you fanless? how is that working for ya?

josh_adnoh
05-21-2009, 11:22 AM
nice lookin engine bay man. Is that a datsun or somethin? pretty cramped in there :bigok:...........loooks like my RB in the 240...

Do you have some pusher radiator fans? or are you fanless? how is that working for ya?

sorry for the confusion but this is not my motor....just took that pic of google to show the ground...but i agree its a nice looking motor..and im not quite sure how the cooling setup is done there???

josh_adnoh
05-21-2009, 11:31 AM
just go and buy a new subharness and sensor and call it a day.

well that is what i have done....i double checked all my wires from ecu to KS...so no need for new wires and i just ordered a brand new genuine nissan KS from ebay...cost me 100$ with shipping....now i need a crank position sensor to turn my engine light off...any body got a good working one for sale???thanks josh

all stock
05-21-2009, 11:46 PM
altho it's rare, make sure to rule out the ECU too.

kcvpr
05-22-2009, 06:38 AM
You can just bypass it with a 1,000ohm resistor...

There is a tan wire coming out of the ecu, that's the knock sensor signal wire. Just cut that (or put crimp on plug connectors so you can switch back) attach the resistor to the the tan wire, and then ground the resistor to something....

Or you could do it like this guy did :

http://wiki.answers.com/Q/Can_you_bypass_the_knock_sensor_if_so_how

96Turbo
05-22-2009, 11:17 AM
^^I don't see why you would ever want to do that unless you're completely broke and don't give a fuck if your engine lasts another week or not. If this is a turbo motor then the KS is a VITAL part of the ecu control system....

I would like my ECU to prevent my engine from blowing itself up when it starts knocking...but that's just me:duh:

josh_adnoh
05-22-2009, 02:55 PM
altho it's rare, make sure to rule out the ECU too.
how can i check the ecu if i can???....and if its still running like crap after,and still getting code 34...then ill know its the ecu

josh_adnoh
06-07-2009, 10:05 PM
well all together now and running,no 34 code,doesn't feel like its doing the v-tec but only took for a quick drive...will post if something happens...thanks alot

ttLOVEjh s13
07-11-2009, 07:20 PM
Man I got almost the same problem as you JOSH.. but my car runs fine, tested and everything, just that damn knock sensor code pops up everytime i reset it after 2 to 3 days. think it might be the sensor too on my car...? what do you guys think....?

please pm me thanks....

UNISA JECS
07-11-2009, 07:23 PM
9/10 its never a bad knock sensor, its a short to ground in the shielded signal wire (very hard to find).

slideways2004
07-11-2009, 09:50 PM
I have a brand new oem knock sensor if anybody needs it. Just send me a pm

96Turbo
07-12-2009, 09:09 PM
9/10 its never a bad knock sensor, its a short to ground in the shielded signal wire (very hard to find).

truf. mine was

Om1kron
07-13-2009, 01:25 AM
I would like my ECU to prevent my engine from blowing itself up when it starts knocking...but that's just me:duh:

last I read knock sensor does not detect knock, it's only purpose is to pull timing. and stiffened mounts can cause them to fuck up.

Autobacs
07-13-2009, 07:31 AM
last I read knock sensor does not detect knock, it's only purpose is to pull timing. and stiffened mounts can cause them to fuck up.

Yes it does detect knock and then retards timing.

It is not foolproof though and it can interpret other engine/car noises as engine knock.

Kaifd3s
07-26-2009, 07:45 PM
anyone have a diagram of the wiring from the ECU to the subharness?