after some "propper" diagnosis my local performance garage has informed me that i need a new det sensor and wiring lume (allthough i told them this when i dropped it off). they're still taking the piss a bit on getting me a quote, however they did say it would take a full day, so i'm estimating about £600 all in.

 

anyone else had one changed at a garage? or is it a do doable job on a drive?

Upper and lower plenums need to be removed. Its not that bad a job, you could do it yourself on the drive.

 

Most people tend to just bypass the Sensor with a 1megohm resistor though. Takes 2 mins and costs 10p.

Upper and lower plenums need to be removed. Its not that bad a job, you could do it yourself on the drive.

 

Most people tend to just bypass the Sensor with a 1megohm resistor though. Takes 2 mins and costs 10p.

 

sorry for being a bit slow, but what are the pelenums? where do you short it? is it actually on the sensor itself?

to what i've in told, my understanding is that the sensors in the block is it not?

 

Is the 1Meg ohm a deffinate? i thought i read somewhere that it was 1ohm. resistor shouldn't be to hard for me to get hold of from work.

 

don't supose it would be a good idea though if the engine actually is knocking.

The Plenum is the Intake Manifold on top of the engine. Their is a 2nd intake below the main one. The Det sensor is bolted to the top the Block inbetween the heads.

 

Definatly 1MOhm. You can either replace it at the connector, which is at the rear of the plenum near the centra of the balance bar, or you can wire it directly at the ECU.

 

The Sensor itself has limited application anyway. It only detects detonation below 3000rpm, as above this the engine noise is too hard for it to filter through. If it senses detonation it then switches to the ECU's Safety map and reduced Boost. If you have a Boost controller than it wont be able to reduce boost anyway, and some aftermarket ECU maps dont even include safety maps.

It can be relocated Jeff @ Zedworld can tell you how 'cos he's done loads !

The Plenum is the Intake Manifold on top of the engine. Their is a 2nd intake below the main one. The Det sensor is bolted to the top the Block inbetween the heads.

 

Definatly 1MOhm. You can either replace it at the connector, which is at the rear of the plenum near the centra of the balance bar, or you can wire it directly at the ECU.

 

The Sensor itself has limited application anyway. It only detects detonation below 3000rpm, as above this the engine noise is too hard for it to filter through. If it senses detonation it then switches to the ECU's Safety map and reduced Boost. If you have a Boost controller than it wont be able to reduce boost anyway, and some aftermarket ECU maps dont even include safety maps.

 

well my boost controller won't go over 6 psi, so i figured that was in safety boost. don't spose you've got a diagram of where to place it on the ecu? spose i could give that a go to see if the boost increases.

its massivly over fuelling, i orrigionaly thought that it was a lamda sensor, but after the "propper" diagnosis, they said both lamda sensors were fine and it was just the det sensor.

It can be relocated Jeff @ Zedworld can tell you how 'cos he's done loads !

 

as in to relocate the whole sensor?

it's easier to replace it at the plug matey, i'll see if i can find you a picture, but or the right hand side, at the back of the plenum under the pass. side wiper ish, you'll see a few connectors, it's a grey one i think with 2 connections, one end goes to the right, the other dissapears down to the block, but there is a connector that is the same, that goes to the VVT solenoid i think, which one end has a white sleeving on, not that one... ya just bung your resistor in the plug that goes to the right (much better with a bit of wire on it, spade connectors and heatshrink over it) I think that's correct... then do a diagnostic, may have to remove your battery for an hour or so to reset the codes, and hey presto, no more code 34 (code 55 means nothing dodgy detected)... much info on here as regards diagnostics if ya search, hope this helps matey, dead easy job, although i did get the connectors the wrong way round when i re-fitted my engine, took me a month to find, haha...

might be of some help if the link woks mate, number '27'....

 

http://www.300zx.co.uk/forums/attachment.php?attachmentid=2116&d=1070304545

 

I have re-located mine, also very easy, but seem to get the very occasional saftey boost at low revs, so gonna try and bypass it see if it makes any difference...

The plug is easier, but if you have break in the loom between the connector and ECU (which is often the cause of det sensor fault in the first place), then it wont help.

 

Doing it as the ECU is the most reliable place. Its between pin 23 and 50.

http://www.twinturbo.net/ttnetfaq/FAQpages/ecuharness.html

yeah, what he said :) I've got a new EFI loom, so never thought of that...

Relocating is a bad idea. Nissan placed it where it is for a very good reason.

 

A Garage can make a quick buck by supplying a new one and relocating, customers happy becuase its fixes the problem, but relocated sensor wont detect properly where it is so its had the same affect as a complete bypass, but just costs a lot more.

excellent guys, very helpfull.

just had a quick phone call with Jeff at Z world (boy that guy knows what he's talking about) i'll deffinatly try shorting it out first and see how it goes. hopefully i won't have to be handing over my hard earned cash to the pesky garage.

jeff fixed my det sensor problem . small resistor and about 30 seconds . that man should ware a cloak and a pointed hat . potter aint got nothing on him

jeff fixed my det sensor problem . small resistor and about 30 seconds . that man should ware a cloak and a pointed hat . potter aint got nothing on him

 

lol yes thats the bypass as discussed above. Very common trick/mod.

Best place for the knock sensor is where Nissan put it.

Next best is a proper relocation job. That's better than the resistor job which just fools the ECU into thinking the det sensor is good.

Resistor bypass is OK for temp solution until you solve the problem. Long-term it means you won't detect detonation which could be very expensive!

Relocation write-up here http://www.angelfire.com/geek/vg30dett/DSR/DetSenRel01.html

Experience from people with all methods here http://www.zcar.com/forums/782735/relocated-knock-sensor interesting to note comment that some ECUs have problem with bypass resistor method.

 

Write up with pics here http://twinturbo.net/net/viewmsg.aspx?forum=technical&msg_id=786419&words=block%3a%3avibrations

i tried to short it out with a resistor, after installing it and resetting the ecu the code came back as 55. so in my success i took it for a spin, then after returning i checked again and the code was back, so i'm guessing it must of come back in as soon as i started the engine? or if the resistor wasn't installed correctly would it still said 34 after resetting it?

the picture shows where i've installed it, does this look right to anyone?

 

 

Sorry the pictures didn't work,

attempt 2

 

[/img]

 

[/img]

Sorry the pictures didn't work,

attempt 2

 

[/img]

 

[/img]

 

[/img]

 

[/img]

 

finally

looks like im guna have to add that to me ever increasing list of things to do! :(