knock sensor ... car runs perfect ... ? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

9524tee · 02-13-2005, 02:05 PM

i have a 95 240 with a ka , and the check engine light keeps coming on , when i clear it , it only comes back on at idle for some reason , never when im driving , or have it in gear . just in neutral while idling . this has been happening for 3 years now , and i still havnt had any problems due to it . the car runs perfect . i run 93 octane on a regular basis too , just seems kinda weird . any ideas ?

*MELLO*SOS* · 02-13-2005, 02:20 PM

Hello

My 92 s13 had this strange problem where it would lose power nearly every time I drove it. It felt to me like the engine was pulling timing for some reason (although MIL wasn't lit). I diagnosed it and pulled the codes to find code 34, knock sensor or KS circuit error. The error would come right back after clearing, even after a few seconds of idling. I tested the wiring going from the ECU to the KS and found that it had a short somewhere. I bypassed the KS by wiring in a 1 megaohm resistor to the KS pin on the ECU, and the problem (power loss) and code 34 have not returned... You might have bad wiring too?

Just a suggestion... My car didn't knock either, btw, and I always run 91 octane (stupid California)

The Hamsterball · 02-13-2005, 08:12 PM

Replace the $30 knock sensor ???

9524tee · 02-16-2005, 09:10 PM

my wiring is fine , no corrosion , and it has never been cut . but if you put a resistor on the line , then what is the downside to doing that , nothing ? and also , just replacing the knock sensor wouldnt fix the problem correct ? becuase if it is going off , that obviously means its doing its job ... or am i wrong on that ?

mjjstang · 02-17-2005, 05:53 PM

Quote:

Originally Posted by 9524tee

becuase if it is going off , that obviously means its doing its job ... or am i wrong on that ?

not really, if its faulty that means its not working as it should, whether it be triggering when it is not supposed to, or not triggering when it is supposed to, either can happen.

vvtisupra · 02-18-2005, 02:32 AM

Quote:

Originally Posted by The Hamsterball

Replace the $30 knock sensor ???

where did you get a knock sensor so cheap. nissan wants 130 for it

*MELLO*SOS* · 02-17-2005, 02:07 PM

Downside is that you don't have a knock sensor so if you run shitty gas or a turbo'd engine you won't have the protection that the KS offers (pulling timing). Replacing your knock sensor will most likely solve your problem, if that is the culprit. I posted what I did because my knock sensor was operational, but the wiring going to it had a short somewhere.

Edit: what code are you getting from the ECU?

Good luck!

Edit: I have had a few people PM me about the knock sensor bypass... Sohere is my post about my KS problems http://www.zilvia.net/f/showthread.php?t=63538 I got my info from a page that explained how to do the process on a 300z, but I've lost that link since

idlafie · 02-18-2005, 02:26 AM

Quote:

Originally Posted by 9524tee

i have a 95 240 with a ka , and the check engine light keeps coming on , when i clear it , it only comes back on at idle for some reason , never when im driving , or have it in gear . just in neutral while idling . this has been happening for 3 years now , and i still havnt had any problems due to it . the car runs perfect . i run 93 octane on a regular basis too , just seems kinda weird . any ideas ?

Anything can cause your Check Engine Light to activate...most are emissions-related. Easiest way to try to figure out what may be causing your problems is read the Diagnostic Trouble Code that is kicked out by your ECU. Have you done that yet?? Knock Sensor codes do not activate your CEL...I had a short in my 95 KA knock sensor circuit & always used to kick the dreaded knock sensor code, (DTC 34) and it never activated my CEL. Your problem is something different. Try pulling the DTC's and go from there.
If you need help trying to figure out how to do that, download a FSM from here:
http://www.zeroyon.com/TheSite/techservice.html
This will better help you troubleshoot your problem.
Hope it helps...
ID

mjjstang · 02-18-2005, 09:46 AM

^anywehre BUT the dealer

m_haiser · 02-18-2005, 10:05 PM

idlafie you are a god. free FSM that is awesome. i hope im not the only retard in the group that didnt already have one....

9524tee · 02-19-2005, 01:51 AM

ok guys , thanks for the info , i will replace the sensor and see what happens , and if that doesnt fix it ... ill post again . thanks , peace .

02-13-2005, 02:05 PM	#1
9524tee Zilvia Junkie Join Date: Nov 2001 Location: Lexington KY Posts: 545 Trader Rating: (0) Feedback Score: 0 reviews	knock sensor ... car runs perfect ... ? i have a 95 240 with a ka , and the check engine light keeps coming on , when i clear it , it only comes back on at idle for some reason , never when im driving , or have it in gear . just in neutral while idling . this has been happening for 3 years now , and i still havnt had any problems due to it . the car runs perfect . i run 93 octane on a regular basis too , just seems kinda weird . any ideas ?

02-13-2005, 08:12 PM	#3
The Hamsterball Zilvia Member Join Date: Jul 2004 Location: CA Age: 39 Posts: 290 Trader Rating: (0) Feedback Score: 0 reviews	Replace the $30 knock sensor ??? __________________ White '90 S13 Fastback (SOLD in '07)

02-13-2005, 02:20 PM	#2
MELLOSOS* LAID OUT Join Date: Mar 2004 Location: LAS VEGAS Age: 43 Posts: 2,015 Trader Rating: (1) Rides Gallery: MELLO*SOS Feedback Score: 1 reviews	Hello My 92 s13 had this strange problem where it would lose power nearly every time I drove it. It felt to me like the engine was pulling timing for some reason (although MIL wasn't lit). I diagnosed it and pulled the codes to find code 34, knock sensor or KS circuit error. The error would come right back after clearing, even after a few seconds of idling. I tested the wiring going from the ECU to the KS and found that it had a short somewhere. I bypassed the KS by wiring in a 1 megaohm resistor to the KS pin on the ECU, and the problem (power loss) and code 34 have not returned... You might have bad wiring too? Just a suggestion... My car didn't knock either, btw, and I always run 91 octane (stupid California)

02-16-2005, 09:10 PM	#4
9524tee Zilvia Junkie Join Date: Nov 2001 Location: Lexington KY Posts: 545 Trader Rating: (0) Feedback Score: 0 reviews	my wiring is fine , no corrosion , and it has never been cut . but if you put a resistor on the line , then what is the downside to doing that , nothing ? and also , just replacing the knock sensor wouldnt fix the problem correct ? becuase if it is going off , that obviously means its doing its job ... or am i wrong on that ?

02-17-2005, 02:07 PM	#7
MELLOSOS* LAID OUT Join Date: Mar 2004 Location: LAS VEGAS Age: 43 Posts: 2,015 Trader Rating: (1) Rides Gallery: MELLO*SOS Feedback Score: 1 reviews	Downside is that you don't have a knock sensor so if you run shitty gas or a turbo'd engine you won't have the protection that the KS offers (pulling timing). Replacing your knock sensor will most likely solve your problem, if that is the culprit. I posted what I did because my knock sensor was operational, but the wiring going to it had a short somewhere. Edit: what code are you getting from the ECU? Good luck! Edit: I have had a few people PM me about the knock sensor bypass... Sohere is my post about my KS problems http://www.zilvia.net/f/showthread.php?t=63538 I got my info from a page that explained how to do the process on a 300z, but I've lost that link since

02-18-2005, 09:46 AM	#9
mjjstang Post Whore! Join Date: Apr 2003 Location: Michigan Posts: 2,654 Trader Rating: (5) Feedback Score: 5 reviews	^anywehre BUT the dealer

02-18-2005, 10:05 PM	#10
m_haiser Join Date: Dec 2004 Location: Newport, OR Posts: 29 Trader Rating: (0) Feedback Score: 0 reviews	idlafie you are a god. free FSM that is awesome. i hope im not the only retard in the group that didnt already have one....

02-19-2005, 01:51 AM	#11
9524tee Zilvia Junkie Join Date: Nov 2001 Location: Lexington KY Posts: 545 Trader Rating: (0) Feedback Score: 0 reviews	ok guys , thanks for the info , i will replace the sensor and see what happens , and if that doesnt fix it ... ill post again . thanks , peace .