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Knock sensor

1123 Views 9 Replies 5 Participants Last post by  vigman, 
G
Ok. Guy I had a 300zx with a z1 ecu and stock boost it ran fine at 9.5 psi I installed boost jets and took it to 12 psi right where I want it but driving down the road I was impressed with the power you all no that feeling lol anyways. After about driving a mile I got on it again and it was only at 6.5 to 7.9. I was like WTF. Brought it home and checked the codes its 34 knock sensor So I started to read about them seem like there known to fail so I looked up the the bypass and tried it. Did it all right but there is still a problem getting the same code after I let it reset and idle for a min or to. So I'm guessing that maby the wires are messed up going to the ecu I'm not sure anyone have any ideas that I can try I'm really tired of my car running at 6 psi been trying to fix it for a couple of weeks now.
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G
Re: Knock censor

Could I just go to the number 23 pin at the ecu and ground it right at the ecu and not have to worry about the code 34 anymore I no the risks and everything but is there any reason why it wouldn't work
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C
Re: Knock censor

You don't ground the knock sensor, you put a resistor inline in place of the sensor. I don't recall the exact value the resistor needs to be, you'll have to search. Be sure you place the resistor on the harness side and not the engine side as it's easy to make that mistake.
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C
Re: Knock censor

Oh and try a little spell check and some proper grammar. You'll get more help if you do.
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G
Re: Knock censor

Well I'm sorry about the spelling phone is hard to type on and changes things with out me knowing but anyways I no I tried he resister. It dosent work at the plug to the knock sensor I'm guessing I have a cut line somewhere I'm not sure so can I do it right at the ecu and if I did how would I all the black wire is is a ground so can I put the resister in at the ecu and ground the other end.
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L
you need a 1m ohm resistor. So long as the wiring from the plug to the ecu is good. If not, you can cut it right at the ecu connector and do the same thing. Do not ground it out, use the resistor across the two pins.
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G
What are the to pins I no one is the number 23 pin so if I put a resister on 23 where else would it go and i have seen 2 diffract things go I need a 1k (1000) ohm resister or something else
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S
read through this post... I knew it had been discussed before ;)

http://www.zcar.com/90-96_tech_discussion_forum/knock_sensor_mod_location_884634.0.html
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G
Fixed it thx guys was using wrong resister lol someone told me 1k 1000 its 1m 1000000 lol car started studdering checked spark all ok so I checked injectors found one with a messed up connection fixed it I thank it's been a problem for a wile cuz it's a hole different car it's amazing god **** I love my Z!
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vigman
You need between a 1 meg to 500K 1/4 watt resistor will do nicely..

Make sure you unplug the old knock sensor, I just cut the old connector soldered the resistor across the left over pigtail...
So if you care to replace the factory knock sensor .. at a later time it's easy to do, well the wiring bit....

Mike
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