Chugging Nissan Primera

I drive a 1992 Nissan Primera wagon 2.0 slx, automatic transmission. Generally the car has been the picture of reliablility. Just lately it “chugs,” especially evident when I’m at low speed of idling. This morning, as I idled for few minutes, the rpm’s fluctuated between 1000 and 2000 rpms, as if I was depressing the accelerator. Any advice, suggestions welcome.



Thanks!

Start with the simple stuff.
Spark plugs, wires, and ignition coils.

Then work up from there.

BC.