JDM_Maximus

ok before you all get mad at me for not reading the stickies.. i did.. i printed it out and went out to check my knock sensor.. set my voltometer/ohmeter on the 20M setting and did as you all said to do.. put it on the pin closest to the front of the car and the other one on the neg battery terminal and it never read anything.. i was wondering if i needed to start the car and have it running for it to read anything with the ohmeter.. didnt want to just do that before asking (dont really know a whole lot about this).. so if anyone that "is experienced" can help please let me know something.. please DONT post unless you are ABSOLUTELY sure about your answer.. i dont need to mess anything up..

thanks

DAVE Sz

iTrader: (2)

Why is it at 20M? The KS should be in the 500k area so setting it to 1M or better yet 10M will be enough. Is your multimeter one of those cheap POS ones? Take the red lead on the ohmeter and touch it to either of the leads coming out of the KS harness connector, take the black one, ground, and touch it to a bolt right between the fuel injectors and the intake manifold itself. Try both of the leads on the harness.

JDM_Maximus

yeah its a POS.. went to wally world and go it.. but anyways.. the settings on it are 20K, 200K, 2M, 20M.. (smallest to largest).. and i have put it on the 200K, 2M, and the 20M to test it.. and it wont read anything.. thats why i was wondering if you needed to have the car running or somthing.. and ive even switched out which leads touch the pin.. and even switched which pins ive touched.. still nothing..
any thoughts on what im doing wrong??

JDM_Maximus

i followed the wire coming from the valley... then unplugged the connecter that was plugged into it.. moved it aside.. and i was checking the harness (that is stationary to the motor by a bracket) and put my red testing rod on the second pin (the pin that is closest to the front of the car, of the two that are sticking up in the harness)..
its the harness that has the pins sticking up in it, not the one that has the holes that the pins go into.. thats the right one right??

UTIMaxima

iTrader: (2)

When testing resistance you should have the ign off, sensor disconnected. red lead on one pin, black lead on the other.

JDM_Maximus

i did that.. and and it wouldnt read anything..

UTIMaxima

iTrader: (2)

That means you have a bad knock sensor.

UTIMaxima

iTrader: (2)

Or a bad meter.

JDM_Maximus

i can tap the testing rods together and it will read stuff.. and i can test stuff with the voltemeter part and it will read.. so i think that it is the knock sensor..

UTIMaxima

iTrader: (2)

You're probably right.

PLUMMAXSE

iTrader: (2)

I just tested my knock sensor and it read 550k ohms. You should set the meter at 2m to be in range. I put the red lead on the pin closest to the front of the car and the black lead on the neg. battery terminal. Your loop is running from the postive lead of the knock sensor to ground. Which is the battery ground. On your meter you should get .500 meg ohms to .620 meg ohms on the 2 meg scale.

JDM_Maximus

i did all that and it didnt read anything at all..

JDM_Maximus

but i can touch the leads together and the read out will change a little bit.. then once i sepereate them it will go up to like 10 or so and then go back to nothing.. so think that the ohmeter is working properly.. right??

PLUMMAXSE

iTrader: (2)

How is your car running? Like crap, is that why you are checking the KS. You could have a open or bad KS. You might need to replace KS, also check that the wiring harness(KS) isn't broken internally.

JDM_Maximus

how would i do that??

Nismo

iTrader: (18)

continuity test

JDM_Maximus

i was talking about ckecking to see if the harness was broken internally..

f550maranello2

iTrader: (2)

You are wrong man, you cant measure the sensor that way, if you notice the sensor itself has only 1 wire running to it not 2. so when u use a meter to measure it it will give you a open circuit. try this take the sensor out. leave it aside for a couple of minutes and let it cool down if the its warm. Then take ur ohm meter set it to the 20M ohm, then measure it 2 times. first take a reading with the red lead on the right prong of the sensor and the black lead to the metal BODY of the sensor then record what u get, second reverse the leads and measure it again and record what you get again. i believe that only one way its gonna give u that 500k ohm reading (if the sensor is good) if it gives u something like 2.5Mohm replace it

f550maranello2

iTrader: (2)

the harnes should be ok. remember there is only 1 wire running to that sensor, even though the plug has 2 wires in it

Igobuk

iTrader: (1)

If you want to test the meter,

just get any light bulb from your car and touch a red lead to one contact and the black lead to another contact. You should get a reading, measure another light bulb of the exact size and you should get a reading that should match the first bulb reading. Then you know the meter is not the one broken.

ThurzNite

iTrader: (13)

True that.

Or if you get a OBD-2 code.

I tested my cracked/bad one vs a new one, and both times the resistance were pretty precise, but not accurate according to the FSM. I tested using 4 diff multi-meters. Maybe the FSM are wrong?

Jae