Sorry for the delay. Busy with work and other projects.

Figuring everything was at least 15 years old (but not many miles) I replaced the plug with standard copper core Bosch plugs (made in Russia), Bremi coils (German) and Bremi wires and boots.

I found a little corrosion on the secondary wiring plugs on the coils and number four plug was oily on body, but not electrode.

Also lightly sanded all the fuse contacts. Some were pretty corroded. Will order the copper ones

Put every thing back together and couldn't believe how great it ran. Dead smooth idle, more responsive. I'm assuming vacuum was up because transmission shifted better(modulator?)

I was afraid to say anything for fear of jinxing something.

Then it sat for a week and when started it had a dead skip on one cylinder. Much more violent than before. It shook so bad in gear I was afraid of breaking something.

Got it in the garage and started it with out the valve cover top plate and skip was gone ?!. All I could think of was maybe one of the coils wasn't grounded which I don't get because of the copper inserts in the coils and small stud on the head. But I took it apart and found a couple of wire connections weren't snapped completely tight. One PO issue is that most of the valve cover plate retaining screws are stripped. Most are replaced with studs and nuts, But I'm afraid to go more than wrist tight on the fasteners.

I also did a compression test and got 145-150-152 on all the cylinders and used a borascope and found the piston dome on #4 has some oil. My scope can't look backwards so I couldn't see the valves. It has 193K miles

So as of yesterday it was running great. Who knows about today.

Latest odd thing is the oil pressure is now dancing around at 1.5 bar at idle. It's always been rock steady. It jumps right to 3 bar on start up and when driving.

Our Jeep does it and it's the sending unit plug gets loose.

Thanks for your thoughts