Knock Sensor

[gr8scott72]

I have my car torn apart right now trying to fix a lack-of-power problem I've been having. My radiator is not blocked and I've already taken the fuel injectors out and sent them off to have them cleaned. They were all fine except the one I damaged when I took it out. (I already ordered a replacement.) The only thing left is the knock sensor. I ordered one from ebay from the link recently listed on here.

I've been talking to an Infiniti tech that said he's done the KS one time and won't do it again. It's too much of a pain. He said that you could relocate the knock sensor to somewhere on the engine that is easier to get to and just extend the wiring harness to make it reach. Has anyone ever tried this? It sounds much easier than getting that lower intake plenum off and all the related timing belt stuff off.

Even if that works, I still have to put the fuel injectors and upper intake manifold back on, which is a complete pain. I hope I can get it back running soon as it's been over 2 months since I tore it apart. (Ran out of money for a couple of months.)

[yodawill2000]

I sure hope somebody knows this trick.Did the tech give you any clue's where he thought it might go ?VERY interesting.

[chingon77]

Sounds like you could add some extend the wires by splicing into the and moving the sensor anywere you want. I wouldn't know though. My car is throwing the knock sensor code right now and don't look forward to having to tear it apart. Were is the sensor located. I looked on the FSM i downloaded for free online and couldn't find were it was located. It shows all the other sensor except the knock sensor.

[gr8scott72]

The KS is under the LOWER intake plenum. The upper intake plenum will take several hours to get off and then you still have the lower one to get to. And the lower intake plenum is part of the timing belt assembly so yeah, I hop I can relocate the KS.

[KUL FIR CHICK N]

I recently pulled ye ol' 500k resistor trick with excellent results. I went ahead and bought the sensor, and I will be doing the re-location. It should still work, but will be less sensitive to knock. I would suggest mounting it somewhere as close to the valley as possible, and definately on a rigid block, manifold, or head surface.

[NismoChi]

here is a pics of it. Yeah i've never replace one on this car, but i had on a VE30DE it was a big PITA, not hard , but again , time consuming. According to the Wikipedia "A knock sensor consists of a small piezoelectric microphone, on the engine block, connected to the engine's ECU. Spectral analysis is used to detect the trademark frequency produced by detonation at various RPM. When detonation is detected the ignition timing is retarded, reducing the knocking and protecting the engine."The knock sensor is located there for a reason, it listen to the knocking (pinging), which happen in the combustion chamber, how can you find a place that is easy to get to but are close enough to the six combustion chamber that you have in your car? Relocating it to a different place, bad idea, IMO.
Modified by NismoChi at 10:39 PM 8/31/2006

[DominickJ30]

The knock sensor is located there for a reason, it listen to the knocking (pinging), which happen in the combustion chamber, how can you find a place that is easy to get to but are close enough to the six combustion chamber that you have in your car? Relocating it to a different place, bad idea, IMO.

Modified by NismoChi at 10:39 PM 8/31/2006

Big X2 on that, its there for a reason. If you want to bypass it just use the resistor trick.

[yodawill2000]

Gotta link to resistor trick ?couldnt find it via search

[greenwar]

Gotta link to resistor trick ?couldnt find it via search

I am interested to know about this as well. Please post a link to the thread if possible.

Thanks in advance.

[gr8scott72]

Big X2 on that, its there for a reason. If you want to bypass it just use the resistor trick.

Wait a minute. You're ok with just bypassing it but not ok with relocating it? If you relocated it at least it would be doing something.

I'm ok with either really. I mean the car has 190k miles on it and I only use 93 octane gas so I'm not too worried about it. I just want it back together and running with more power than a honda civic dx.

[NismoChi]

I'm thinking about the same thing, too. Bypassing it with a resistor is only for a temporary fix or, to see if the engine response any differenerty with it bypassed. anyway, here is some info you can read if you want to test and/or bypass it.http://www.cardomain.com/ride/748507/9

[yodawill2000]

Need to find that connector on my J.

[rdorman]

It took me a while to find this one.......

http://twinturbo.net/net/viewm...86419

[gr8scott72]

It took me a while to find this one.......

http://twinturbo.net/net/viewm...86419

Holy crap!!! Great find!! If it's good enuf for a 600hp monster, it's good enuf for my daily beater. Guess I'll be putting my car back together myself instead of paying someone to do it!!

[yodawill2000]

Riddle me this .The sensor just fits snugg on the outside of the lower plenum ?Interesting..

[chingon77]

Ok. After taking some stuff apart and making a feeble attempt to take apart the upper plenum, and I also got a $2700 quote from the dealership to replace the KS for me. I'm going to have to opt for this relocation tip. So I take it the original knock sensor just stays in the engine were ever it is and you don't have remove it? All have to do is just buy a new K.S. and sub harness into a new location? Seems easy enough.

[rdorman]

Yes, the old KS just stays put. Let us know how it goes!

[chingon77]

Ok thats what i thought. I ordered the sensor and should get by the end of the week. I'm having trouble finding the sub-harness for it. It looks like there's only 2 wires needed so i figured i'll make my own damn harness with a little bit of cable, soldering, heat shrink and a little love. It would also keep excess wires to a minimum.I'll keep you guys posted.

[gr8scott72]

Ok thats what i thought. I ordered the sensor and should get by the end of the week. I'm having trouble finding the sub-harness for it. It looks like there's only 2 wires needed so i figured i'll make my own damn harness with a little bit of cable, soldering, heat shrink and a little love. It would also keep excess wires to a minimum.I'll keep you guys posted.

The harness is part # 24078-30P00 and I bought it at my local dealership last week for $24.

[Q45tech]

The harness is like a shielded audio cable [to avoid ignition radiated rf/noise from riding back to ecu on the KS center conductor]........the mounting bolt provides the ground connection.

[Defiant]

Riddle me this .The sensor just fits snugg on the outside of the lower plenum ?Interesting..

Back in Ye Olden Dayes, when knock sensors began their ascent and we wrenchers were all proclaiming with glee the banishment of the air pump, it was a common engine bay trick to walk around to the back of a running engine hooked up to the Allen machine and while the endeavoring mechanic was all but deafened by the mighty roar of strangled power under the hood (where his head was, probably pondering why GM in all its glory had not only chosen to make the distributor hold-down bolt not only completely inaccessible without the special $60 Snap-On wrench that was fabricated by welding a long, incredibly-contorted rod onto a box end, but they had also chosen the remarkably bastard size of 16mm, which no wrench set had ever previously contained), we'd surreptitiously tap on the tailpipe with a wrench. This would make the knock sensor suddenly come to life and destroy whatever progress the poor blighter was on the verge of making in his tune-up endeavors.

The knock sensor, as stated earlier, is tuned for certain discrete frequencies. Even on a V block, it should do its job from most places on that hunk of iron.

Speaking of iron, I've heard rumour that tyres are now being made of rubber. Hell, that'll never work. How do you rivet them onto the wooden wheels?

[yodawill2000]

Thanks for the Chuckle defiant.

Reminds me of how things were back when I was the Kid cleaning engine Parts for my Dad in a bucket of Kerosine .LOLGood times.

[chingon77]

Hmmm...Ok makes sense. I have some copper sheilding tape that I use to sheild my guitars electronics from interference. I wonder if wrapping the copper shielding around the tape would work? I would incase it heat shrink tubing after so it wont be exposed. But would that shield need to be grounded? hmmmm

I'm calling around for the harness and dealers i've called so far don't have them in stock and they cost $36. And the 1 dealer that does have it in stock is charging $46.

[yodawill2000]

Call Joe at everythinginfinti.com

[chingon77]

My K.S. arrived today and I didn't want to wait and order a harness online so I ended up finding and buying a sub harness at a dealer. I poped the harness on and looked for a place to stick the sensor. The way the K.S. is mounted on the picture on the twinturbo site were this tip comes from looks a little different then the J30 plenum. So I had to figure out a place to mount the K.S. I ended up mounting it in the center of the plenum towards the back were the brace for the 2 throtle cable are mounted. I actually mounted the K.S. right on top of the brace. It's the only place I could find to mount it at the moment because I was pressed for time. I think I might have to relocate it. I'm thinking because the K.S. is sharing the same bolt as the throttle cable brace and the K.S. is mounted on top of the brace that it may effect the sensitivity, also the bolt only goes in about a inch into the plenum. I'm going to have to buy longer bolts.I drove about 80 miles around town after and so far so good. The engine light did come on again so I checked its not the K.S. anymore its only the EVAP sensor now. The car drives normal again and doesn't feel slugish. I also feel a little bit more kick then usual from the engine. I'm wondering if it has anything to do with the can of BG 44k i put in the tank the other day.I'll give an update later on how this works out.

Now I have to figure out how to fix the Evap sensor, its the only code thats being thrown now. Anybody have any tips for this?

[rdorman]

Chingon77, thanks for posting your results. Mine is throwing the knock codes and I did not want to pull it down to replace. My car to is sluggish, particuarly at throttle tip in, largely from a stop. If you floor it, it runs great.

[gr8scott72]

Call Joe at everythinginfinti.com

It was cheaper at my local infiniti dealership.

[yodawill2000]

Did you call Joe and let him know you were Nico Material ??

[rdorman]

For the VE30DEhttp://www.4dsc.com/articles/d...shtml

Joe's prices:Knock sensor: $126.14 Ea.Harness: '90-'93: $96.25 ------- '94-'96: $31.59

[gr8scott72]

For the VE30DEhttp://www.4dsc.com/articles/d...shtml

Joe's prices:Knock sensor: $126.14 Ea.Harness: '90-'93: $96.25 ------- '94-'96: $31.59

I got a brand new ks off ebay for $60 including shipping and got the harness (1993) from my local infiniti dealer for $24.