Ok, im having a little bit of a problem. When at cruise or wide open i pretty much get a constant 4 degrees of knock retard.. No matter what it is pulling 4 degrees, Now sometimes at wot i will get pinging with no knock retard and it won't retard the timing at all. But then i will have no detonation and will still get 4 degrees... Now im thinking that my sensor is pretty much worthless now because of my engine, It does make a lot of noise combined from valve train and the pistons im running along with the headers and everything else... Right now the knock sensor doesn't seem to be doing me any good at all because its not preventing the pinging, but is retarding when there is no pinging going on...

 

you really running the 98 with a 383? i might have some ideas for a 99+ but dont know anything about 98 and older.

if you can hear pinging and it isn't being picked up by the pcm then yeah your knock sensors are worthless. if you can't figure out how to make them work you might be better off with nothing and doing it oldschool(ears/plug readings). the knock sensors should be able to hear the knock way before you so just saying you can't hear it doesn't mean it isn't happening but if you can hear it and there is no reaction from the pcm then thats no good at all.

my motor is prety loud, i think the forged pistons slap around a little when cold and the valve train sounds like a sewing machine. with this i dont get any false knock. i get some false(i think) when i go from decel to acel, i think it is my motor shifting and the exhaust hiting the frame.

 

a built motor will "knock" anyway. mine sounds like a small diesel sometimes! you may want to try to "detune" the sensors a bit. i was able to loosen mine up a bit by removing them, putting a little dab of silicone in the hole, and then just tightening it back up by hand. the silicone will act as a bit of a dampener. quick, cheap, and easy.

jim, you don't have your motor welded to the frame yet?

 

Yup im running a 383 in my 98 .. One thing also about the 1st gen vortecs is they only use one sensor on the side of the block, maybe problems similar to this is why they went to multiple sensors in the intake valley. The other thing im thinking is that possibley im getting so much false knock from engine noises that its throwing it off when there is real knock. What i think im going to try to do first is decrease the knock attack rate. Its set at .65 right now and i read that someone decreased theres to .200 and got rid of the problems they where having with knock retard due to engine noise. I think i will try that along with retarding the timing 4 degrees all across just to be sure i don't get detonation... Also there is the possibility that i just have a bad knock sensor, but im not sure if the symptoms of a bad sensor are the same as what im having

 

definately try a new sensor but the fact that you can hear knock and it isn't reporting any seems really odd. i think real knock is louder than ANY other motor noises that may be seting it off. on the 99+ i think it will learn to pull timing before the knock sets it, it is called knock learn. it is definately a performance killer if it is not real knock.

 

I get a lot of knock on tip-in PE. As soon as I hit the throttle, and it will go away that quick. I also get it sometimes on a real hard shift. I think it's false.

 

Ok i did some logging tonight and found this out... Anything above 1/4 throtlle at any rpm is showing 4 degrees kr. So its getting that amount no matter what, so i looked at my max kr table to see if maybe its just being limited to 4 degrees, but it is allowing up to 9 degrees of kr.. So something somewhere is making enough noise to call for 4 degrees all the time, now what im thinking is maybe at wot even when there is audible detonation its not enough of a increase in noise from the false kr to retard the timing even more.. So what im thinking is that if i decreased the sensitivity it wouldn't pick up on whatever engine noise is causing the kr but would be able to pick up on the real kr.. Maybe the false kr is confusing it. I was also comparing my kr rate to a stock table and there the same, so i think that might be playing a factor. How much of a decrease is a good decrease? i read somewhere on here that i guy was having similar problems to what i was having and set it to .200 all across for the kr activity rate and didn't have any more kr problems and it still worked with real knock.. Who knows

 

Have any of you had succesfull results with desensitizing? i read on a search that you tried parish but didn't have any good results and just went with wiring a resisitor

 

when i had FALSE knock just puting a 10kohm resister inline with the sensor worked great. i tried one night to tune it out and had no luck at all.

i was sure my knock was false, i dont know what you have going on there.

 

Ya i have a whole can of worms, its not detecting real knock so as far as im concerned the sensor is worthless as of now.. What i will probably do is just take 4 or 5 degrees of timing out in the tables and then try to desensitize the knock sensor and if that doesn't work ill try a knew sensor first or just disable them and go to the old school methods