I tried searching for somebody else who has run into this situation. I am running 730ECM with s_AUJP v4 for my heads/cam/intake L98. My problem is, when the engine is warmed up and the car goes into closed loop at idle, I'm getting small amounts of knock retard. The car currently idles at 800rpm I get no knock counts while the car is warming up. I've tried adjusting timing between 17* and 31* along with leaning out or richening the fuel and I get no change, the computer is still pulling timing. It will still show knock retard after warmed up. the amount of knock retard is very small. Half of the time, it's showing less than 1* and will sometimes go to 4*. When driving, BLMs are in the 120-124 range and I've even done a few 3/4 throttle runs and I get no knock retard at all while driving.

The motor does seem to shake a lot more now with the new ZZ409 cam, and we checked for anything hitting or vibrating that would trip the knock sensor, but found nothing. The ONLY thing I can think of is that at idle in neutral with my foot off the clutch, there's gear chatter coming from the transmission as a result of the cam shaking the motor. The sound goes away when the clutch is pushed in but I can hold the clutch and the knock retard will still continue. When i step on the gas, the knock retard goes away immediately. I can even step on the gas ligtly and hold the RPMs at 1000 and the knock retard will go away, but the moment it tries to idle again, the knock retard comes back.

My next move will be to pull the plugs, but I highly doubt that it's knocking. Is there any way to possibly desensitize the knock sensor at idle? or is there another way to help with these knocks at idle?

 

maybe moving the knock sensor ?

http://tunertools.com/proddetail.asp?prod=MSD-8964

http://www.ronfrancis.com/prodinfo.asp?number=KB-41

I bet rbob knows the answer.!! I don't believe that a memcal's knock board would work with another frequency like a 305 knock ?

 

Set this value higher then the idle speed:

You just may be correct!

RBob.

 

RBob, you are the man! Thanks!