I have been under this car 100 times looking for anything that is banging.It seems to get knock randomly .It has 91 octane fuel in there.But it dont' seem to matter what octane I run in it. Haven't tried race fuel lately though.

I just got a new knock sensor to install and have an lt4 km already in there.
This knock is robbing power and driving me nuts. I guess might have to get some programming to wipe it out if nothing else works.

Anyone else have weird knock at times on their lt1 and if you fixed it would like to know how. I have replaced fuel filter and injectors.
I have not replaced wires,plugs or opti. I do have a new fuel pump to install and an afpr also.
I can richen or lean things with my maft but it seems to have no effect on this knock.I can get it just revving it up at lights but its worse on full throttle runs.It can hit 10 on my scanmaster sometimes.I am sure its costing me consistency and power.

 

I seem to have the same problem and i have not tracked it down yet. I will be replaceing my knock sensor in a few weeks and if that does change things i will just put a resistor in and turn the knock sensor off when im raceing and useing 100 octane. I'll let you know if i find out the cause of this. I'm really stumped on this one.

 

Hmm we both have lt1 scanmasters.I wonder sometime if its that but my ls1 scanmaster work perfect.And had one in my dsm also.

I do also see some weird 02 readings after a wot run. I dont see it but the scanmaster shows like 700 something which would be stupid lean but have done fuel pressure tests and they show ok. But I have new pump and reg anyway and changed out filter even went to gm filter. Have newer 30 pound
svos.
You have at least new plugs and wires and stuff..I am thinking it was opti or maybe lifters..betting on lifters maybe .They seem a bit noisy to me.
but of course changing lifters like plugs and wires in the lt1 is no fun at all.

I may do the resistor but thought it worked only on 95 and earlier or does it also work on our 96 and newer. I like the idea of doing it in programming and one buddy has lt1 tunercat so can maybe do it for me.I am about ready to do it ,its so very frustrating.Took car to track and it runs x et and mph one run and y the next sure do to the stupid knock. I think will throw in some xylene or toluene soon and make sure its not octane related but why would a near stock z28 get knock on 91 or 92 octane. I have tried gasohol 92 also with not much luck. My ls1 seems to be random knock free.

 

When i was on the dyno some knock showed up so i know im getting it.

The resistor mod can be done on OBDII vehicles. I think it just takes a different resistor.

And i thought about just tuneing it out when i was on the dyno but i liked the resistor mod better so i can turn it on and off, its just safer to me. Being able to pick up real knock if it does happen.

 

Well update on my old post. I recently changed out fuel pump for racetronix,changed fuel filter and changed out reg for adjustable fast one and dialed it to 44 psi line off.
I also go injectors pro cleaned thru the rail. The car dont seem to lean out most runs like before it would get leaner and leaner top end. But I still see knock retard even when running 94 octane. I am pretty sure its false as have seen it with o2s showing in the 900 when set to factory fuel afr. I know have tunercat/jet program and already got annoyed enough to take out burst and part throttle knock. Now think am going to wipe out full throttle for now but may put it back when add spray or forced induction.
I could play maybe with attack and decay settings for knock also. I have been under this car and fixed some banging stuff like catback on rear end brace thing. But knock is still there. I also recently changed knock sensor and put in another different lt4 km. Nothing helps. Time to wipe it in programming. I only run premium in the car so really can't see a problem with no knock sensor. Quite a few cars never even came with them and starting to see why. I also have massive knock retard phantom knock problem in my 91 laser. I had it also in my 92 talon. My 99 trans am and 97 talon and 91 talon don't have it. Damn this phantom knock crap. I have programming in my 91 talon and 97 talon to take it out and my 99 ls1 never had it.