Wiring up a knock sensor need help

[Hillkill]

Alright I guess I haven't had it wired the whole time I have been driving it but now I want to have it. Someone told me that if I don't have it connected it pulls timing and richens up my A/F mixture. I don't want that any more because my car bogs before boost. Can anyone tell me which wire goes where. I have the knock sensor with one side of the plug and thats it. I looked at my ecu and the pin where the sensor is suppose to connect is missing. Even weirder is that the connector is missing of the wiring loom. So I was wondering which of the two wires from the knock sensor goes where. One is black and one is white. Any help is appreciated

[float_6969]

Are you sure you're looking at the right pin? I've never heard of a CA missing the knock sensor wire. It should be on pin 23 and should be plain white. Please see my attachement.

As for black and white, the white is the signal wire, and the black is the grounding for the shieilded wire that you need to use.

[fraz]

If you are not worried about running the knock sensor, you can connect a 10k Ohm resistor between pin 23 and ground. This will give an 'ok' signal to the ecu and it wont knock back the timing.

edit: you need a 1M ohm resistor (1,000,000 ohms)
Modified by fraz at 11:56 PM 8/7/2005

[slownslurious]

****'s sake finally! I've been wondering how to do that for like 4 months now. Thank you.

[iliketocrash]

its generally a bad idea to bypass the knock sensor if you do'nt keep a close eye on a/f ratio, egt temps and know how to recognize the problem itself when you hear it. but if you're confident that you know what you're doing then just bypass it.

[Hillkill]

If I wire it back up do I connect the ground to the chassis or the ecu ground? thanks for all the help so far.

[fraz]

if you use the actual sensor, its just a 1 wire thing, the sensor uses the block as the ground signal.It has a piezo element inside it that changes resistance when it detects knock.If its not connected it pulls 10deg timing under 3500 rpm

If you do the resistor trick, just do it on the back of the ecu and connect it to one of the ground wires (black) on the ecu plug

[Hillkill]

Let me get this straight if I want to wire the knock sensor back up I have to wire up the white wire to the ecu and not worry about the black wire. Just want to double check before I fry my ecu.

[iliketocrash]

you won't fry your ecu unless you for some reason wire the ecu to your battery instead of the knock sensor =)

[Hillkill]

I won't fry my ecu, but i just wanted to know what to do with the extra black wire from the knock sensor

[float_6969]

As I said before, the extra black wire simply gets connects to a ground somewhere. It doesn't matter where, just a ground.

[Hillkill]

thanks , time for me to go wire her up

[slownslurious]

if you use the actual sensor, its just a 1 wire thing, the sensor uses the block as the ground signal.It has a piezo element inside it that changes resistance when it detects knock.If its not connected it pulls 10deg timing under 3500 rpm

If you do the resistor trick, just do it on the back of the ecu and connect it to one of the ground wires (black) on the ecu plug

so you can just wire the resistor inline with the sensor wire (assuming it is grounded?) it would probably be safer just to wire one end to the ECU and the other to ground, if I understand correctly.

[fanta]

Make sure to use shielded wire.

[slownslurious]

lol... why? you use shielded wire with the stock one lest inteference screw up the resistance reading. but if youre wiring a 10ohm resistor to the ECU I really don't think its an issue.

[fraz]

You need a 10K ohm resistor, thats 10,000 Ohms

You want to cut the white wire that comes from pin26 off about 2-3 inch from the ecu connector, strip the end, and also strip a little of the insulation from the black wire that comes from pin 20, solder a 10K resistor across and tape it up.

Done

edit- sorry guys, my mistake. it is pin 23 not 26. I have been working on a fwd and they have a different wiring diagram

edit2- just checked, you need a 1M ohm resistor, 10k is not enough

Modified by fraz at 11:30 PM 8/7/2005
Modified by fraz at 11:57 PM 8/7/2005

[fanta]

lol... why? you use shielded wire with the stock one lest inteference screw up the resistance reading. but if youre wiring a 10ohm resistor to the ECU I really don't think its an issue.

I thought you'd be using the sensor.

[float_6969]

NO, the whole purpose of the resistor is to SIMULATE the sensor so that the ECU thinks that it is present. If you're going to wire up the resisor you don't need the sensor wired up. THAT is the point of the resistor.

[Hillkill]

Well I wired up the knock sensor to the ecu and my safc using some wire from my old loom, seems to work but a loose conection at the maf is messing with my gas mileage. I also picked up a couple of resistors too but I think I got the wrong ones 10 ohm and 1k ohm. Oh well . thanks for all the help

[slownslurious]

sorry, typo.

You need a 10K ohm resistor, thats 10,000 Ohms

You want to cut the white wire that comes from pin26 off about 2-3 inch from the ecu connector, strip the end, and also strip a little of the insulation from the black wire that comes from pin 20, solder a 10K resistor across and tape it up.

Done

[fanta]

NO, the whole purpose of the resistor is to SIMULATE the sensor so that the ECU thinks that it is present. If you're going to wire up the resisor you don't need the sensor wired up. THAT is the point of the resistor.

I knew this.

[onevia1800cc]

You need a 10K ohm resistor, thats 10,000 Ohms

You want to cut the white wire that comes from pin26 off about 2-3 inch from the ecu connector, strip the end, and also strip a little of the insulation from the black wire that comes from pin 20, solder a 10K resistor across and tape it up.

Done

pin 26????? i thought it was 23

[slownslurious]

should be 23 I'm pretty sure, my head says yes but my FSM's stupid ECU pin out diagram is cut in half (damn pdf version!)

[onevia1800cc]

my pinout says 23!

BUT ATTENTION!!!THE RESISTOR TRICK DOESN'T WORK!!!i had a guy put one in on mine (PROFESSIONALY the guy does electronics for a living) doesn't work at all!i am going to hard wire my KS back in todaydidn't have a knock code before now i do. also there is a big difference too in the engine performanceyou can tell it pulls timing

[slownslurious]

ok then we should lynch mob on the guy that said that it does work. There has to be an appropriate resistor to bypass the sensor, however, I just don't know what that is. I hardwired my damn sensor and its still throwing the knock sensor code and pulling the timing so WTF am I supposed to do cause it sucks! (can't afford a new one)

[onevia1800cc]

at least i know my knock worked before i wouldn't even know where to begin with the right ohmage

[slownslurious]

anyone have a used knock sensor.... how can I check to make sure mine is bad?

[onevia1800cc]

i hard wired mine really easy ran fine till i tried that resistor crapi'm guessing you don't have the connector???

[slownslurious]

nah the guy that did my harness wire mine thorugh the harness, it threw the code, I hard wired it, and it still throws the code and runs bad. I have the connector and everything.

[slownslurious]

HEEELLP MEEEEE