Seraphic

Ive been making preperations to fix the z, ive ordered injectors, both bypass and pcv hose kits. hoping that my injectors are the cause of my problems. the next thing on my list to get is a new knock sensor, but i cant locate it. (upper plenum is out) anyone help me find it ? pics would be nice

Mousier158

The detonation sensor is located on the top of the engine block on the rear of the engine. basically once you locate the EGR valve if you look straight underneath on the block its right there.
http://www.300zx-twinturbo.com/cgi-b...fault&total=70
Know that it is imposible to reach this unless the transmission or engine is removed from the car.

this article is a way to deactivate the sesor if this is an option for you. http://www.300zx-twinturbo.com/tech/index.html

91zxtt

Not exactly.....The knock sensor is located under the lower plenum. The tranny doesn't begin to get in the way. I don't think you can remove it without removing the EGR valve; which is a major bitch. I replaced mine with the engine in the car and I never touched the tranny.

Here's a better picture. The knock sensor goes inside the black box.

v0va

how do you know when your car is detonating?

91zxtt

You have to listen for it.

It sounds like marbles in the intake.

v0va

is there any other way? because i think my exhaust is too loud to hear anything like that

Mousier158

according to your meathod 91zxtt, yes that is one way to do it...or i suggested to remove to trans and go at it from the space you clear by doing so. this is if you want to leave as much of the engine in tact as possible.

Seraphic

can you show me how to remove the egr, or if theres a tutorial somewhere. also, if im removing that, does the lower plenum gotta go too ?

bardabe

I think it's alot easier to just move your motor forward. from what I notized whn I pulle dmy motor if you remove the heater hozes from the back. and soem harness clips that hold it to the fire wall. then take the radiator aling witht he shrud and fan. looseng all the mounts. trann too. take off the shifter and drive shaft. movethe motor forward till it hits the AC and you have plenty of room to work on. other wize it's a death defying stunt to try and pull it offsince the EGR does have a 3foot bolt that wont clear witht he Fire wall. btu that's just how I'd do it.

Seraphic

nah, i dont have the knowledge to do that then put it back. removing the upper plenum was a job within itself considering the fact this is the only car ive actually worked on. ill gladly do it the hard way, if someone can show me how

Mousier158

To do this task the way everyone else has been posting...YES the lower intake has to be taken off. The EGR valve need be unbolted from both the upper and lower intake but thats the extent. EGR removal/replacement http://www.ttzd.com/izcctech.html

CanyonCarver

Fact, Here's a writeup on relocating the det. sensor. You leave the old one where it is, buy a new one and a new harness.

http://www.angelfire.com/geek/vg30de...tSenRel01.html

Fact, I haven't done this so I don't know how it works. It looks relatively simple.

Theory, It's prolly not as effective as the factory location........

bardabe

That write up si weaksauce I don;t jknwo what the hel it's talkign about

Seraphic

i guess i'll get to work on removing the lower plenum. so once i take it off i should see it, correct ?

91ztt - is it a bitch to take off the lower as it is the upper plenum ? because man, i hated~ taking off the upper plenum. itll be in my nightmares forever

bardabe

go tot he begingin of his thread (mod upadtes) and you'll see. he had fun. right 91tt?

91zxtt

Yep. It was a real f*ckin' picnic.

The lower plenum is considerably more difficult to remove than the upper.

Mousier.....Have you actually replaced the knock sensor that way? I've had the tranny out of my car and from what I recall, there is no way in hell that there will be enough room to get to the knock sensor that way. It'll be hard enough to remove the EGR that way. The water tubes for the heater core inlet and outlet WILL get in the way.