89 renix pinging all the sudden

At freeway speeds under moderate throttle I get a noticeable ping.
My knock sensor has been out for years and just passed smog.

Only change was a new Felpro blue valve cover gasket.

My scanner reads good head Temps with ECT relocated to the stat housing, so I'm stumped on the cause of my new issue.

Gotta love this jeep, not a day goes by without popping the hood open and commenced to wrenching.
And a understanding wife who also has a 95 ZJ that is always "acting funny"

my2monkeys said:

My knock sensor has been out for years and just passed smog.

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That should rule out too much spark advance.

If you are confidant with your measured engine temps, OK.

That leaves crappy fuel and carbon buildup in the combustion chamber.

Have you pulled the plugs for a look-see?

I've had three Renix so far that would run lean at around 2000-2500 RPM, usually a steady pedal to mildly accelerating. All three times it turned out to be an O2 sensor issue, either the O2 itself, wiring cooking on the exhaust manifold or oil soaked connectors. It may progress from pinging to bucking. You may have caught it early.

Generally three main causes of pinging in my experience, lean fuel, timing or low octane fuel.

Like Hypoid said the plugs can be a good indicator. The best way to check is a good run up the interstate, pull into a parking area, check the plugs hot. The plugs may carbon back up a touch at lower RPM's and may fool you. I usually just check the 2 and 3 plug as they are easy and quick to get to.

Renix are notorious for the manifold bolts backing out, lean means either to little fuel or too much air. The programming seems to have a little issue with trim, near peak torque RPM's and certain vacuum situations.

Replacing the knock sensor may stop the ping, that is what it is there for. Most of the time when I had a ping on any of my vehicles they were getting too hot. Have you checked the fuel pressure under the ping conditions? X2 on pulling plugs and inspecting them ALL!!!