Random, single detonation count.

[kaj750]

Installed new lifters. Broken in with assembly paste, high zinc oil, and zinc additive.
Car started and ran great. Still does except:
When idling, I get a random detonation knock. It's only one and it's approx every 5-10sec while idling.
I do have EFI so wondering if I contaminated the O2 sensor with all the stuff that's in the oil right now.
I the only other thing I've noticed is that the volt meter is showing around 12v. I know these cars are sensitive to power and ground.
The only source of oil pressure I have is the OEM gauge. At idle, it shows 60 at start up and same when warm.
This car continues to do weird-assed crap that I've never seen.

Ideas?

 

[Geoff 2]

I doubt you have detonation in neutral.

 

[j-c-c-62]

I doubt you have detonation in neutral.

All it would take is a random errant or mis-read signal instructing the ECM to ignite a single spark way too early, regardless of throttle position. First determination would seem to be is it random, cyclic, and/or the same cylinder.
No matter what, I am only spit balling here as this is above my paygrade.