LT1 POWR

Well with the tuned OBDII-OBDI conversion in my sig i would get up to 8º of knock on my scanmaster under light throttle. I had a LT4 KM and Ion desensitized the KS a little. I put my stock PCM back in and im still getting it but not as much. Its like the OBDI PCM magnified the knock. I was running 92 octane but im running 91 octane now and im sure its false. I have checked all the spark plugs to make sure they are tight and a few other things and i dont know where to look anymore.

Im getting a dyno tune later today and i would like to know where im getting this false knock from before i go in. Is it normal for LT1's to get some knock like this. I notice this morning that after driveing for about 30 min it went away for a while but then i came back again. Im stumped on this one. Please help me out.

VintageMuscle

I don't know what type oil your using, but I was shocked how much 10W40 helped my KR......I tried everything. I was attempting to quiet down the valvetrain a little by using a heavier oil, and the result was the KR issue went away.

My noise makers are forged/floating pistons, roller rockers and headers but I use an LT1 KM.

LT1 POWR

Im useing Mobil 1 fully synthetic 5w-30 for the colder winter months but i useually use a 10w-30 when it warms up. I dont remember if i had this same problem with the 10w-30 though. Would different oil viscosities cause something like this.

VintageMuscle

I was using 10W30 all year round, and to answer your question, I can only tell you my personal experience which just happened last week.

I used 10W40 to try and quieten it down some, and my KR issue disappeared, which was unexpected.......but GREATLY welcomed nonetheless.

Zigroid

go here first:
http://shbox.com/1/4th_gen_tech2.html#knock_sensor

I had 8 degrees of false knock in my engine. I ended up doing the resistor mod as a quick band-aid and eliminated it. With no other changes the car ran 5 mph quicker in the 1/4.

Injuneer

Can we assume Ion modified the OBD-I PCM internally, so it would work with the 100Kohm knock sensor in your 96?

LT1 POWR

Yes. But im going back to OBDII now so that shouldnt be a problem.

LT1 POWR

Do knock sensors ever "go bad". If not what else could be causeing this false knock.

Zigroid

my knock sensor was bad, it was reading all messed up numbers. Looking back on it I should have just replaced the knock sensor but that would have costed money, we already had the resistor to do the mod.

1racerdude

Put your knock sensor on a switch and turn it off when ya race and on for everyday.
Do a search there is plenty of info on how to install on a switch and with the resistor.
LT4 KM has never cured a retard problem for me.