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M35 Knock Sensor Wiring Stripped -advice Please

malialipali

By malialipali,
in Four Door Family & Wagoneers

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malialipali Enthusiast

malialipali

Posted
Posted (edited)

So I just did the belts on the stagea and low and behold whilst flashing the light about I see some bare wires.

I'm assuming it's the knock sensor , it's a two wire plug between the v under the intake. Can be seen from the front in the opening between the heads. One wire is bare other looks to be cut. (Looks like mice got to it :-/)

Car does not ping.

So my question is. Does the intake have to go in order to get to it and fix the wiring ? If so should I just do the rocker cover gaskets(passenger side weeps only just) and plugs 143xxxkm. Or am I going beyond what's needed to get to the knock sensor.

Car goes beautifully just last weekend did 1000km round trip and got 720km out of a tank (ultimate ) with no hesitation what so ever even snapped the speedo on a overtake.

Thanks for any and all advice.

Edited by malialipali
scotty nm35 Grand Master

scotty nm35

Posted
Posted

Surprisingly common, I have had to repair a few. I should have a spare knock/injector loom here somewhere if you can't find something local.

Yes the lower plenum needs to come off to replace it.

scotty nm35 Grand Master

scotty nm35

Posted
Posted

Nice and warm Dale, for many hours. Smart little f*krs would just nest it out with rags and grass, anything they can find to make a cosy and protected home.

As soon as the door unlocked they would know to scurry away.

malialipali Enthusiast

malialipali

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  • Author
Posted (edited)

Surprisingly common, I have had to repair a few. I should have a spare knock/injector loom here somewhere if you can't find something local.

Yes the lower plenum needs to come off to replace it.

Is the wiring shielded? If not I can repair the plug thats not an issue. If it is shielded then yes I would need the part.

Is there a part # ? Same as the VQ35s? by any chance. Is this the guy I'm looking for https://www.z1motorsports.com/oxygen-and-knock-sensors/z1-motorsports/350z-g35-vq35de-knock-sensor-sub-harness-p-5833.html?osCsid=keol7gu21kictn9cop24pqrhb4

If I cant find anything by end of tomorrow, I'm happy to pay what it cost + express bag postage Scotty.

OK just did a quick google (currently at work so cant dedicate too much time) looks like 50ohm RG58U coax on the positive side. 99% confident I can repair it. So will give it a crack to repair the wire.

If the car ends up off the road for a few days so be it - ive got a spare.

Cheeky little feckers they are...

I was actually joking when I said looks like mice got to it o.O , now I find that this is actually true and common. WTH!

May as well dot the plugs since I'm gonna spend next Saturday over an engine bay.

Anything else I should to preventative wise. Not fussed on $ , I'm driving the car to Adelaide next month and need to make sure its healthy.

Thanks a bunch on the help All .

Edited by malialipali
scotty nm35 Grand Master

scotty nm35

Posted
Posted

You had better get it apart and see what's broken first, you may need the knock sensor too.

Yes, that loom looks similar, on ours it's wired into the injector harness, but you can simply run that one in addition to replace the chewed out part.

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malialipali Enthusiast

malialipali

Posted
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Posted (edited)

So spent most of the day (38C here today) over the engine bay listening to tunes and drinking beer.

Stripped the intake off, rigged up a hose to my wet and dry vac and vacuumed up sand/ grit, dirt 2 snail shells ??????? (where the hell do they come from) from around the intake before taking it apart.

Cleaned the intake sections with carb cleaner . Got the harness out and assesed. Looked like shit!. stripped it back de-pinned the connector. Soldered in new leads. Coax wire was perfect fit. Soldered the pins and reassembled the connector.

Knock sensor tested at 562K Ohm (well within the range). With the harness it tested at 559K Ohm still in range.

Did the spark plugs at the same time, who ever did the car last should be slapped !!! had Champion Platinums in there with a 14 (NGK4) heat range .... way too hot , guess they whacked in 350 plugs, electrodes were worn to heck too probably 1.4-1.5mm gap. Got some LFR6AIX.

Put it all together and the moment of truth, fired up first go. Went for a test run , Significant improvement on take off, tried stalling it up and lit up the rears ! never happened before.

I think I just thought these cars were good at WOT and sluggish otherwise......... proven wrong now. Very very happy with the improvement.

Thank you all for your help , Esp Scotty for telling me the whole intake needs to come out.

Total cost $123.70 including the plugs (had to buy the coax and I ran out of heatshrink)

Edited by malialipali
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