Knock retard -- is this real or not?

[Fred 86 GN]

During a run, this happens 2-3 times, typically around 4200-4400 rpm, in second and third gear mostly. The A/F ratio drops below 9:1 on the DS screen (what the ECM is calling for, supposedly), and the next half-dozen frames (running 18 frames per second) show the following KR amounts -- 1.8, 1.2, 0.9, 0.6, 0.3. Sometimes it only gets part way down then starts again -- 1.8, 1.2, 1.8, 1.2, 0.9, 0.6, 0.3. Sometimes the 1.8 value causes a "knock count", sometimes not. So I only see 1-3 "knock counts" in a run typically.

Does not seem to occur during shifts (those happen around 5000rpm and the engine falls back to 4000rpm or so).

Anyone else see this sequence?

Should I be concerned, even though the values are low?

O2's can be 760 to 820mV during this event...doesn't seem to matter.

Thanks,

 

[Russ Merritt]

Me too, 8.5 air/fuel ratio (what computer is calling for) only I have false knock! When I floor the car and the boost starts up, the knock counts go from 2 or 3 to 25-30 in 2.25 sec, then they stop. I had Red A. put a 3 sec knock delay in the chip and all is well. after the three sec 18# 94 oct 0.0 knock the rest of the pull, little fat though 860's 02 (I know you can't count on 02's that much but...) Yours sounds like real knock, cause it's later in the pull after the car is settled down to making power. 1.8 is nothing though, I would even worry. Did you try giving a little more fuel? Some cars like to run fatter than others. Just my .02