S13 Bad Knock sensor Question - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

TheJDMpanda · 03-12-2014, 06:47 AM

My KA24DE is chugging gas like crazy. Code 34, which is the knock sensor code, comes up. Is this what's giving me poor gas mileage? Or could it be something else? I had a bad Coolant Temp Sensor as well which made my MPG around 12-15 and erased the codes. Now it's at least at 14-17. I need to check my connections for it.

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cbeuglas · 03-12-2014, 08:02 AM

Bad knock sensor will retard the timing affecting gas mileage. Replace the sensor (pain in the ass). The other way is to put a 1 mega ohm resister in line. There is a write up somewhere. If you are running a na ka setup the resistor trick will work fine. Cut the plug off the knock sensor not he harness side. Jump the two wires with the resistor (resistor between the two wires). Plug new resistor plug you made back into engine harness and clear the code and your done.

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TheJDMpanda · 03-12-2014, 12:32 PM

Quote:

Originally Posted by cbeuglas

Bad knock sensor will retard the timing affecting gas mileage. Replace the sensor (pain in the ass). The other way is to put a 1 mega ohm resister in line. There is a write up somewhere. If you are running a na ka setup the resistor trick will work fine. Cut the plug off the knock sensor not he harness side. Jump the two wires with the resistor (resistor between the two wires). Plug new resistor plug you made back into engine harness and clear the code and your done.

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Thanks! I'll look at it soon as it could also be the sub-harness. Maybe the insulation melted or something. I'm running a stock KA at the moment and yes if it was for you saying it retarded the timing then I wouldn't have clearly known it was the sensor.

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cbeuglas · 03-12-2014, 08:05 AM

Z1 motor sports sells a pre made resistor plug for this for the z32. It is the same for the z. It is a plug and play part.

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TheJDMpanda · 03-18-2014, 08:09 AM

Quote:

Originally Posted by cbeuglas

Z1 motor sports sells a pre made resistor plug for this for the z32. It is the same for the z. It is a plug and play part.

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Does the Z32 resistor plug work with the KA harness? Or is that just for reference?

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cbeuglas · 03-12-2014, 08:09 AM

http://www.z1motorsports.com/product...oducts_id=5580

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cbeuglas · 03-12-2014, 12:40 PM

The sensor harness is a pain to replace might as well do the sensor also. Good luck

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cbeuglas · 03-12-2014, 12:42 PM

The sensor reads 5 volts in and 2.5 out in working condition. If it reads 5 in and 5 out it sees it as a knock.

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TheJDMpanda · 03-12-2014, 12:44 PM

Quote:

Originally Posted by cbeuglas

The sensor reads 5 volts in and 2.5 out in working condition. If it reads 5 in and 5 out it sees it as a knock.

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TheJDMpanda · 03-12-2014, 12:43 PM

Thanks. True. One quick questions. Ive seen the write up but do you know if the sensor is attached to the block where the intake manifold is or below it?

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TheJDMpanda · 03-12-2014, 12:43 PM

Check that with a voltmeter right?

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cbeuglas · 03-12-2014, 12:47 PM

It's under the manifold. Almost centered. You kind of have to use the sub harness as a way to guide the sensor in and out.

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cbeuglas · 03-12-2014, 12:48 PM

Maby even tape a coat hanger taped to it to reinstall it.

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cbeuglas · 03-12-2014, 12:59 PM

Yes volt meeter. The sensor is located under the manifold almost in the center of the head. Unbolt the sensor and uses the sub harness to pull it out. To reinstall use a coat hanger taped to the sensor and sub harness. To help guide it back in place. It is a real pain. If you are replacing the harness replace the sensor also. It's a 2 wire connector from under the manifold on the front of the engine.

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TheJDMpanda · 03-12-2014, 06:04 PM

Quote:

Originally Posted by cbeuglas

Yes volt meeter. The sensor is located under the manifold almost in the center of the head. Unbolt the sensor and uses the sub harness to pull it out. To reinstall use a coat hanger taped to the sensor and sub harness. To help guide it back in place. It is a real pain. If you are replacing the harness replace the sensor also. It's a 2 wire connector from under the manifold on the front of the engine.

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I might have done this wrong. I've never done this. I took the multimeter and put it in DCA 20. I hooked the negative to the negative battery cable (ground) then I took the positive and put it in both of the holes in the plug that is in the engine harness not the sub harness for the knock sensor. I got 3.239 on one side and then I got .002 in the other. Again I'm still learning. Probably did it wrong. Please correct me

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zerodameaon · 03-12-2014, 01:27 PM

Just fix the problem, don't waste 16 bucks on that plug when for 6 bucks more you can do it the right way and get a new sub harness from wiring specialties. Or if you are deadset on the resistor go buy a resistor for under a buck and do it that way.

http://www.wiringspecialties.com/connectoru.html

TheJDMpanda · 03-12-2014, 01:31 PM

Quote:

Originally Posted by cbeuglas

It's under the manifold. Almost centered. You kind of have to use the sub harness as a way to guide the sensor in and out.

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Ok ill try to do that this weekend.

Quote:

Originally Posted by zerodameaon

Just fix the problem, don't waste 16 bucks on that plug when for 6 bucks more you can do it the right way and get a new sub harness from wiring specialties. Or if you are deadset on the resistor go buy a resistor for under a buck and do it that way.

http://www.wiringspecialties.com/connectoru.html

I will get both as well. Just to save the pain of having to change either in the future. Lasts longer.

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Juantwo3 · 03-13-2014, 11:12 PM

I am currently battling this same issue i replaced my knock sensor it was cracked also replaced the sub harness with it, reset the light same knock sensor code comes up i cut the wiring harness open and traced the insulated wire till it splits off into 3 black wires one goes into the engine bay the other 2 go to 2 plugs. I checked for continuity from side plug side B and #27 on the connector for the ECU, it has continuity what the hell am i doing wrong

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tom_sr20 · 03-14-2014, 01:42 AM

[QUOTE=Juantwo3;5583136]I am currently battling this same issue i replaced my knock sensor it was cracked also replaced the sub harness with it, reset the light same knock sensor code comes up i cut the wiring harness open and traced the insulated wire till it splits off into 3 black wires one goes into the engine bay the other 2 go to 2 plugs. I checked for continuity from side plug side B and #27 on the connector for the ECU, it has continuity what the hell am i doing wrong

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how do reset the code? by removing the negative battery terminal?

TheJDMpanda · 03-14-2014, 04:39 AM

[QUOTE=tom_sr20;5583226]

Quote:

Originally Posted by Juantwo3

I am currently battling this same issue i replaced my knock sensor it was cracked also replaced the sub harness with it, reset the light same knock sensor code comes up i cut the wiring harness open and traced the insulated wire till it splits off into 3 black wires one goes into the engine bay the other 2 go to 2 plugs. I checked for continuity from side plug side B and #27 on the connector for the ECU, it has continuity what the hell am i doing wrong

Sent from my iPhone using Tapatalk[/QUOTE

how do reset the code? by removing the negative battery terminal?

Either with the battery terminals or go on the passenger kick panel (LHD) take the long thing on the door the one that is on the door frame, take the 3 screws for the kick panel, there's 2 10 mm bolts holding the ECU. You will need a flat head screwdriver to turn the screw on the ecu. Turn ignition on (dont start) turn knob to the counterclockwise all the way until it stops (dont force it) leave it there for about 2 seconds, turn the screw clockwise again. (Just in case you dont know how to get to the ECU) and all you have to do after its in self diagnostics, do the same all over again but dont turn the ignition off. Leave it on. All you are doing is doing it twice basically. Counterclockwise, 2 second hold, Clockwise, hold it for a bit, counterclockwise, 2 second hold, and clockwise. You should get code 55 if you did it correctly (Sorry for my english)

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Juantwo3 · 03-14-2014, 08:39 AM

[QUOTE=tom_sr20;5583226]

Quote:

Originally Posted by Juantwo3

I am currently battling this same issue i replaced my knock sensor it was cracked also replaced the sub harness with it, reset the light same knock sensor code comes up i cut the wiring harness open and traced the insulated wire till it splits off into 3 black wires one goes into the engine bay the other 2 go to 2 plugs. I checked for continuity from side plug side B and #27 on the connector for the ECU, it has continuity what the hell am i doing wrong

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how do reset the code? by removing the negative battery terminal?

No i have an obd1 scan tool that has Nissan from 89-92 i can clear the code

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TheJDMpanda · 03-14-2014, 02:26 PM

[QUOTE=Juantwo3;5583385]

Quote:

Originally Posted by tom_sr20

No i have an obd1 scan tool that has Nissan from 89-92 i can clear the code

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Is it the consult? The way I did mine was with the screw on the ECU. My cleared out but as soon as I started it, it popped up again. Its not engine. The engine is healthy and mileage isnt high. I also do oil changes on time. But I'm not sure how to use consult if its that

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Juantwo3 · 03-14-2014, 02:55 PM

No its an auto logic scanner, and i dont need help clearing the code lol i need help fixing the problwm

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TheJDMpanda · 03-14-2014, 02:58 PM

Quote:

Originally Posted by Juantwo3

No its an auto logic scanner, and i dont need help clearing the code lol i need help fixing the problwm

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Ohhhhhh sorry my bad! Haha well I would check all connections, cables, and power sources if you haven't. Maybe its not just the cable. Maybe there's a cut wire or something lurking around haha. I could be wrong again lol

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03-12-2014, 06:47 AM	#1
TheJDMpanda Leaky Injector Join Date: Nov 2013 Location: Hurlburt Field, FL Age: 23 Posts: 69 Trader Rating: (0) Feedback Score: 0 reviews	S13 Bad Knock sensor Question My KA24DE is chugging gas like crazy. Code 34, which is the knock sensor code, comes up. Is this what's giving me poor gas mileage? Or could it be something else? I had a bad Coolant Temp Sensor as well which made my MPG around 12-15 and erased the codes. Now it's at least at 14-17. I need to check my connections for it. Sent from my Samsung Galaxy S4

03-13-2014, 11:12 PM	#18
Juantwo3 Zilvia FREAK! Join Date: Sep 2011 Location: DTFullerton Age: 30 Posts: 1,101 Trader Rating: (20) Feedback Score: 20 reviews	I am currently battling this same issue i replaced my knock sensor it was cracked also replaced the sub harness with it, reset the light same knock sensor code comes up i cut the wiring harness open and traced the insulated wire till it splits off into 3 black wires one goes into the engine bay the other 2 go to 2 plugs. I checked for continuity from side plug side B and #27 on the connector for the ECU, it has continuity what the hell am i doing wrong Sent from my iPhone using Tapatalk __________________ GO DUCKS!!!!!!!!!

03-14-2014, 02:55 PM	#23
Juantwo3 Zilvia FREAK! Join Date: Sep 2011 Location: DTFullerton Age: 30 Posts: 1,101 Trader Rating: (20) Feedback Score: 20 reviews	No its an auto logic scanner, and i dont need help clearing the code lol i need help fixing the problwm Sent from my iPhone using Tapatalk __________________ GO DUCKS!!!!!!!!!

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03-12-2014, 08:02 AM	#2
cbeuglas Zilvia Member Join Date: Apr 2013 Location: United States Posts: 265 Trader Rating: (2) Feedback Score: 2 reviews	Bad knock sensor will retard the timing affecting gas mileage. Replace the sensor (pain in the ass). The other way is to put a 1 mega ohm resister in line. There is a write up somewhere. If you are running a na ka setup the resistor trick will work fine. Cut the plug off the knock sensor not he harness side. Jump the two wires with the resistor (resistor between the two wires). Plug new resistor plug you made back into engine harness and clear the code and your done. Sent from my SAMSUNG-SGH-I337 using Tapatalk

03-12-2014, 08:05 AM	#4
cbeuglas Zilvia Member Join Date: Apr 2013 Location: United States Posts: 265 Trader Rating: (2) Feedback Score: 2 reviews	Z1 motor sports sells a pre made resistor plug for this for the z32. It is the same for the z. It is a plug and play part. Sent from my SAMSUNG-SGH-I337 using Tapatalk

03-12-2014, 08:09 AM	#6
cbeuglas Zilvia Member Join Date: Apr 2013 Location: United States Posts: 265 Trader Rating: (2) Feedback Score: 2 reviews	http://www.z1motorsports.com/product...oducts_id=5580 Sent from my SAMSUNG-SGH-I337 using Tapatalk

03-12-2014, 12:40 PM	#7
cbeuglas Zilvia Member Join Date: Apr 2013 Location: United States Posts: 265 Trader Rating: (2) Feedback Score: 2 reviews	The sensor harness is a pain to replace might as well do the sensor also. Good luck Sent from my SAMSUNG-SGH-I337 using Tapatalk

03-12-2014, 12:42 PM	#8
cbeuglas Zilvia Member Join Date: Apr 2013 Location: United States Posts: 265 Trader Rating: (2) Feedback Score: 2 reviews	The sensor reads 5 volts in and 2.5 out in working condition. If it reads 5 in and 5 out it sees it as a knock. Sent from my SAMSUNG-SGH-I337 using Tapatalk

03-12-2014, 12:43 PM	#10
TheJDMpanda Leaky Injector Join Date: Nov 2013 Location: Hurlburt Field, FL Age: 23 Posts: 69 Trader Rating: (0) Feedback Score: 0 reviews	Thanks. True. One quick questions. Ive seen the write up but do you know if the sensor is attached to the block where the intake manifold is or below it? Sent from my Samsung Galaxy S4

03-12-2014, 12:47 PM	#12
cbeuglas Zilvia Member Join Date: Apr 2013 Location: United States Posts: 265 Trader Rating: (2) Feedback Score: 2 reviews	It's under the manifold. Almost centered. You kind of have to use the sub harness as a way to guide the sensor in and out. Sent from my SAMSUNG-SGH-I337 using Tapatalk

03-12-2014, 12:48 PM	#13
cbeuglas Zilvia Member Join Date: Apr 2013 Location: United States Posts: 265 Trader Rating: (2) Feedback Score: 2 reviews	Maby even tape a coat hanger taped to it to reinstall it. Sent from my SAMSUNG-SGH-I337 using Tapatalk

03-12-2014, 12:59 PM	#14
cbeuglas Zilvia Member Join Date: Apr 2013 Location: United States Posts: 265 Trader Rating: (2) Feedback Score: 2 reviews	Yes volt meeter. The sensor is located under the manifold almost in the center of the head. Unbolt the sensor and uses the sub harness to pull it out. To reinstall use a coat hanger taped to the sensor and sub harness. To help guide it back in place. It is a real pain. If you are replacing the harness replace the sensor also. It's a 2 wire connector from under the manifold on the front of the engine. Sent from my SAMSUNG-SGH-I337 using Tapatalk

03-14-2014, 01:42 AM	#19
tom_sr20 Join Date: Apr 2012 Location: Guam Posts: 33 Trader Rating: (0) Feedback Score: 0 reviews	[QUOTE=Juantwo3;5583136]I am currently battling this same issue i replaced my knock sensor it was cracked also replaced the sub harness with it, reset the light same knock sensor code comes up i cut the wiring harness open and traced the insulated wire till it splits off into 3 black wires one goes into the engine bay the other 2 go to 2 plugs. I checked for continuity from side plug side B and #27 on the connector for the ECU, it has continuity what the hell am i doing wrong Sent from my iPhone using Tapatalk[/QUOTE how do reset the code? by removing the negative battery terminal?