NHVett

My knock sensor is new, and reads 300 K Ohms on a good quality DVM. Anyone know if that is normal for an 85 Knock Sensor?
I'm having all kinds of timing problems and am looking at all related possibilities. This condition has existed since the engine rebuild.


[Modified by NHVett, 7:50 AM 8/4/2001]

SouthernSon

Did you torque the sensors more than 15 #/ft. If torqued more they will not work correctly.

NHVett

Yep, betcha that's wot eye did. Crapola!


[Modified by NHVett, 1:29 PM 8/4/2001]

hi-tek-vette

the sensor is probably way to tight ......sensor should read 9.5 to 10 vcolts @ no detonation, less than 1 volt means it is sensing detonation, or is damaged

hi-tek-vette

by the way, do you see a code # 43 ??? thats set by detonation ........ or the sensor thinking so .......

vettenuts

Don't know about 85, but a 90 should read 3,300 to 4,500 ohms from sensor terminal to ground. I imagine 85 would be of similar values such that 300 ohm may be indicating a problem. I would remove and check resistance between pin and housing. If still 300, you may have damaged it during installation.

cohocarl

I printed out a thread from over ago (Just found it) that recommended a 4.5k to 5k ohm 1/4 watt resistor to bypass the knock sensor on an 85. I just got back from Radio Shack with a pack of 4.7k ohm resistors, soldered a couple leads to one and "replaced" my knock sensor with it. I just got done with an engine swap in my 85, and I think I may have whacked the side of the sensor when I was lowering the motor into it's mounts, and was unsure of it's operation. I just got back from a quick ride and it seems to be crisper (if you know what I mean). No check engine light. I got on it a couple times after I got all the fluids warm and I didn't hear any spark knock either. I had a 68 camaro with 10.5/1 ratio, so I know what spark knock is. Will play with the Gtech tomorrow....wife getting a little annoyed......

Later,

Carl :yesnod:

hretter

That's what I did, too - overtorqued it. I backed it out, retorqued to 14 lb ft and no water leak at the sensor and code 43 went away. Thanks.

AmoriFati

I used teflon tape and then torqued it. Not sure if it did what it was supposed to do, to minimize false knock.

Tunedport90

85-89 is 100k ohm ks

AZSP33D

Problem is that the pipe thread is not deep enough to engage the KS more than 50% so people apply more torque... especially since this has coolant behind it, so none of us want it to back out or leak coolant. Best solution is to chase the threads with the 1/8 NPT tap (I think that's what it is) either at overhaul or with grease to try to trap the metal bits from invading your cooling system, and then install with a light coating of teflon Pipe Dope. Teflon tape is nicer to clean up and remove, but it's not as good of a seal for 20psi of coolant or steam.