Civic HX wizards I need help.

[glweek]

I have a 1997 HX with 180k on it and am getting a ping starting around 2100rpm with even the slightest load. The spark plugs are NGK ZFRF4-11 with an OEM distributer cap and NGK wires all replaced about 10k ago. Timing is set to 12* as indicated in my Haynes manual. The Timing was checked with the jumper installed causing the check engine light to stay on, idle at 670ish checked with a gun with perfect red mark indicated as well as OBD2 reader also showing exactly 12.0* between 667-677rpm.

Its been happening for a while, but not getting any worse. I also have possible piston slap, first start on cold mornings till the motor warms a little. I have but haven't gotten around to installing a new fuel filter and have a pressure checker but have not checked compression yet. EGR valve was cleaned about 10k ago as well. Been raining for a while and no garage so can't check the valves at the moment.

What else do i check?

[Daox]

Are you sure its pinging? Try premium fuel for a tank?

[glweek]

In all honesty, I don't know its actually pinging. I've never had it pointed out to me by an experienced person. Now that you bring it up, can you hear a ping on every cylinder? The timing of the sound and rate of the ping at the specific engine rpm only really sounds like its coming from one cylinder maybe. I'll throw some 91/3 octane next fill up and see if that changes anything. If it does or doesn't what does that indicate?

[DSMHondaGuy]

How clean / dirty are your fuel injectors?
Have you checked compression? (Carbon build up can raise compression)

[Daox]

If it stops, it is likely pinging. If it doesn't stop, it may still be pinging, and maybe not.

Seeing as you've checked all the OEM timing settings, I would think its probably not pinging. Have you checked for rattles? That would happen at specific RPM ranges. Pinging would more so be under heavy loads (lots of throttle).