I have just swapped in a JDM b16a and have all of the wiring perfect to my knowledge and i get the check engine light at higher RPM's. The code is 23 and thats knock sensor. Now my question is what does the knock sensor do? and right now its running on 87 pump gas because thats what i had left in the tank from before the swap

-Matt

 

I believe the Knock sensor measures vibrations and when I knock happens it spikes or something like that,.....

 

ok... so would that code be knocks from running low octane?

 

possibly .... I'm noit fully familar with the causes of knock ...however the ZC is a japanese engine and therfore would require higher octane

 

sorry... my name is really decieving(sp) i clarified i have a b16 in my origonal post (it was always there:P)

 

yeah thats me not paying attention

anyways is the B16 a Japanese engine because if so my last words still apply ...?

 

i had 87 in my car before and NO check engine light came on, car ran fine.

Are you sure your timing is set properly?

 

There's a couple things you should/can do.

First thing I would do is grab a voltmeter and make sure that the knocksensor is working properly. After that's done, make SURE that you have the correct plug going to it because there are like 2-3 plugs that'll fit.

After thats done, try running better fuel (higher octane), back off your timing a degree or two.

If this still dosnt help, then you'll need to replace the knock sensor and also I'd make sure that the wiring is shielded. For some reason the knock sensor is picky about that stuff.

 

yeah
i never changed the timing on the engine
i used the JDM plug and i had to wire it in... im pretty sure i didn't use sheilded wire though...

to check it with a voltmeter what is the resistance supposed to be?

i can retadrd the timing with the dizzy right?

 

yeah that wire has to be shielded the reason why is the knock sensors signal can be easily confused with electrical noise....

 

JDM motors have a tendency for having a bad knock sensor when then get over here, its a common problem...also it could just be wired up wrong

did u do the timing belt/water pump on it before installation? check your timing with a timing light and adjust as needed

I'm leaning towards faulty sensor or bad wiring though

 

if its a jdm motor you need premium fuel, everyone i know with JDM engines uses sunoco ultra 94

 

u dont need to use premium...I know lotsa people that use 91 with no problems...but then again it depends on where u get it from

personally I really dont like sunoco gas...I have always got the worst mileage on it no matter what car

 

ok, im rewireing the knock sensor with sheilded wire. but while im up there how do i test the knock sensor to make sure its working properly?

 

^ get a timing light, knock on the block with the backside of a screw driver, if you see hte timing start to retard, the knock sensor is working.

 

is there any other way? like to take a multimeter and check the resistance or something?

 

I don't think there is a way to test the knock sensor... it's a piezo electric device which induces a voltage according to vibrations that it feels. Highly doubt you can do a resistance check on it.

 

knock is such a pain to resolve.

I had the same issue.

I ran a shielded wire, double checked everythnig twice over, replaced the sensor, everything i could think off and still got knock...

It was messed up cuz, apparently knock is only used up to a certain rpm, like 4K or so. After that, it's basically disregarded by the ecu. My knock would appear once i hit vtec.. P28 solved that.. No knock sensor at all!

 

is there some way i could tease the ecu into thinking that the sensor is there but there is no knock sensor hooked up if the sheilded wire doesn't help?

 

What ecu you running?

I think the best solution would be to get it chipped with a program that disables knock.