Knock Sensor!

[LA_phantom_240]

Ran into another snag in project 'Quit riding in my damn s14 and get your s13 running, asshat!'. Got the motor stabbed up, in the motor mount slots, and started bolting up the tranny and what not... and started plugging up the harness in my buddy's s13. He calls me over as I'm peeking under my hood and staring at my crank seal and how much it's leak pisses me off, and points to a wire on the harness, near the coolant temp sensor, and its pretty long with no connector on the end. He goes, "What's this?"... Being a smartass I replied, "A broken wire, dumbass. Great job, when did you do THAT one? Find the connector and solder it back together." He peeks around for a minute and asks, "where the FUCK does it go?"

Stumped because I don't remember taking this wire off when we pulled the motor, I grab my flashlight and look at my s14's motor and see it runs under the intake runners to the block. I assume this is the knock sensor. Well apparently he didn't have one on his motor before it blew up, and doesn't now as well.

What's the best way to go about installing one, without taking the intake apart? What will happen with no knock sensor hooked up? I realize it will retard the hell out of the timing, and told him and he actually came up with a question that I couldn't honestly answer: Why don't we just advance the shit out of the timing to counteract the knock sensor missing?

[louisdaboois]

honestly, its alot easier to just take the intake mani off to get to the knock sensor. Sadly enough, its only held on by a 10mm bolt, iirc. I could be wrong, but I believe the knock sensors readings only pull timing when its under load. If you were to advance the shit out of it to compensate, then it may interfere with the motor idling because the ecu isnt seeing a load or increase in air intake.

[LA_phantom_240]

honestly, its alot easier to just take the intake mani off to get to the knock sensor. Sadly enough, its only held on by a 10mm bolt, iirc. I could be wrong, but I believe the knock sensors readings only pull timing when its under load. If you were to advance the shit out of it to compensate, then it may interfere with the motor idling because the ecu isnt seeing a load or increase in air intake.

True, true.

I'm just gonna tell em to fuck it til he can get a sensor and maneuver it in there.

[wickedS14]

Do what I did, instead of taking the mani off just lower the knock sensor into the intake directly above the hole. Then take a long extension and manuver it in between the intake and with the extension push the bolt through the knock sensor and into the block. Tighten it down, then with your hands just pull the plug back to the front of the block. Its a real tight squeeze though. If you manage to drop it like I did a few times, just grab a wire hanger and fish it back out. Good luck.

[LA_phantom_240]

Great idea! And I have some 11" long needle nose pliers we used to fish a couple hoses around in the bay.

[makulit054]

you might be able to reach from underneath the car. It you can't then you are going to have to use some adapters and extensions. It's doable.

[UNISA JECS]

You just need a 18-24" 3/8 extension, 3/8" universal extenion (tape it to make it firm and not move so easily and a 12mm 6pt socket and you will be good to go, an dyou have to move some of the fuel hardlines out the way because you will go threw runners 2 and 3.

[deuceforty]

you dont have a knock sensor on there??

whatever you do DONT get on from a dealership (200 bucks) or even autozone/advance auto (120)

i bought my UNISA JECS oem replacement knock sensor from autozone for 120 plus tax, sold the motor, and ended up selling the sensor for 45 shipped...

its 62.97 on rockauto.com

[Anto]

you cant do it without a wobble extension. heres a hint- dab grease on the end of the bolt to hold it on the socket. use a coat hanger to manuver the ks through the inatke mani. ive done this three times before & the hardest part is getting the bolt into the ks into the block.

[LA_phantom_240]

you cant do it without a wobble extension. heres a hint- dab grease on the end of the bolt to hold it on the socket. use a coat hanger to manuver the ks through the inatke mani. ive done this three times before & the hardest part is getting the bolt into the ks into the block.

I was thinking grease or maybe silicone LOL.

How does the KS work anyway?

[Anto]

500kohm resistor, when it knocks the resistance goes down I think? not sure

I know you can run without one, get a radioshack or newegg 1megaohm and wire it to the corresponding pin on the ECU, then to ground.

make sure your timing is right and you're running GOOD GAS

otherwise poof.

[jackjack]

if i remember correctly................ i removed the intake and radiator hose. after loosening it, i was able to stick my arm through the intake manifold and get the bolt out. i didnt wanna mess with the whole "swivel, tape, grease, make sure you dont drop the bolt" thing.

[fliprayzin240sx]

Go under the car, thats how I did my SR after I forgot it after changing bottom ends...

[LA_phantom_240]

if i remember correctly................ i removed the intake and radiator hose. after loosening it, i was able to stick my arm through the intake manifold and get the bolt out. i didnt wanna mess with the whole "swivel, tape, grease, make sure you dont drop the bolt" thing.

I got fatass arms, and my friend isn't much smaller. Plus he's a pussy.

[fliprayzin240sx]

I got fatass arms, and my friend isn't much smaller. Plus he's a pussy.

Go make new friends... :bigok:

[Sileighty_85]

How does the KS work anyway?


www.wellsmfgcorp.com/pdf/counterp_v4_i4_2000.pdf (http://www.wellsmfgcorp.com/pdf/counterp_v4_i4_2000.pdf)

[makulit054]

Here's a few links to help explain what and how knock sensors work.

www.wellsmfgcorp.com/pdf/counterp_v4_i4_2000.pdf (http://www.wellsmfgcorp.com/pdf/counterp_v4_i4_2000.pdf)

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

[projectRDM]

You can bolt it to the head as well, although it won't pick up knock as frequently it will get enough of a reading to not throw a code. I've done that a few times without issue on customer's cars.

[LA_phantom_240]

Good info guys, thanks!

[wiggafly808]

i bought my UNISA JECS oem replacement knock sensor from autozone for 120 plus tax, sold the motor, and ended up selling the sensor for 45 shipped...


.. to me!

Ill be following this http://www.socal240sx.org/articles.html

I might just suck it up and take off the intake mani if i have time

[deuceforty]

.. to me!

Ill be following this http://www.socal240sx.org/articles.html

I might just suck it up and take off the intake mani if i have time

glad you got it man :)

good doing business with you!