I had the valves done about 40k ago. Is it normal for a timing chain to go on a car with 130k?

I haven't noticed any drop in performance except for when the stuttering happens. I'm assuming that the drop in oil pressure is due to the drop in RPM. It stutters only after it clicks with only one stutter per click. It sounds like some sort of clutch trying to engage that then slips. Anything in terms of fuel supply I should be looking at?

Re the Vacuum pump- what should I be looking for other than leaks, or broken connections?

I don't want my timing chain to go and deal with THAT kind of horrific repair, but I want to rule out simpler things first.

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85 300D 180k