93 park ave-picks up a shake

my '93 is in pretty shape-with 345000 kms on her now- she as tight as the first day i drove it.lately though while normal driving she will pick up a shake that feels like the motor is crooked. shes like this for 4-10 seconds then right back to normal.anyone have this before?

i wrote the above-please respond to milligan71---thanks

Replace the plugs, wires, fuel filter and check your fuel pressure would be a good preventative maintenance function, if not recently done.

Usually, what you have described is called, "spark scatter", in mechanic slang.
By the way, “spark scatter” is caused by applying high voltage from the coils, to weak wires or, worn out plugs. Electrical current will travel the source of least resistance. In auto engines, that "least resistance" source is the nearest ground!

thanks hotz28-seems that was the problem-runnin like a new one now🙂