Auto tapped the SS and it is getting 4 degrees contant K/R at WOT. Add to that the other variables, and its getting anywhere from 16 to 22 degrees K/R. Ive heard of others who had this prob and never heard the solution. The car has a split Dur. nitrous cam with the stock tune. i know its running a little lean but we cant figure out the constant 4 degrees. Anybody out there have a clue?

 

Do you have a MAFT to add fuel?More fuel will ussually help knock retard.

 

You have a cam, stock tune, and you're running lean on that stock tune.

I don't know what to tell you! <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

 

you getting any codes? if one or both of your knock sensors are bad it will pull 4* all the time, my back one did this.

 

Dont really know if your being sarcastic or not but the heads have been hogged out , so yeah...it runs lean on the stock tune. The car will be tuned Sat. As far as codes goes, It throws the normal "multible misfire code " but no knock sensor codes. I did notice though that the right O2 was reading a little lower than the left side. Also, I was out in it today and noticed that there is an off idle miss, like when you are taking off from a red light. BTW the car is a stick.Going to A/tapp again later today so i can get a little more info. Also,Iwas looking in the edit and noticed that in one of the knock sensor tables had 4 degrees across the board. Anybody have a clue ? This is on the stock tune.

 

Cammed cars are prone to misfires at idle. If it's here or there I wouldn't worry about it. However if you're getting a boatload of misfires at idle, there may be an issue. Possibly pertaining to tuning. Keep in mind, the number of misfires that A-Tap shows is double what it really is because A-Tap samples every 200rpm. So if you get 4 misfires showing, it's really 2.

4 Degrees of KR constantly could be mechanical too. What size pushrods (are they possibly bent on the misfiring cylinder(s)) and how many inch/lb did you torque them down to when installing them. I wonder if there is slack somewhere in the valvetrain that is causing your KR, misfire, and misfire off-idle as you accelerate. Is your EGR system working too?

I think it's a combonation of the tuning and something mechanical causing your problems.

I went through tons of KR issues and valvetrain causing false knock after I did heads and cam.

I went one size bigger on the pushrods to see if I took the slack out, the knocking would stop. Unfortunately, the next size up was just enough to leave valves hung open bleeding cylinder pressure and the engine wouldn't start. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> So I took them out and put the stock sized chromoly pushrods I had originally put in when I did heads and cam and progressively torqued them to 22 inch/lbs (if memory serves me correct), started it up, and all my knock went away (except for tuning issues I knew of). By me simply doing that, I wonder if the place that built my motor didn't exactly torque the rockers down properly or set them up with lash (which is near impossible on an LS1 unless you have really small fingers <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> ).

Just some food for thought.

 

I have the exact same problem! I got my car on the dyno for the first time this past weekend. I have an A4 though. I was picking up knock from 3,100-6,100! Check out the numbers in my sig. Anyone have any ideas?

<small>[ March 17, 2003, 12:38 PM: Message edited by: Jay 2001 TA ]</small>