ok guys, i'm new at this, but here is my question. i have a 92 5.0 and the car has 110,000 miles one, but still drives strong. this car is my daily driver and it hadn't given me a problem until now. i was driving from california
and midway it started doing this. i get to around 55 to 65 mph and then my engine kind of revs up and down while i'm driving steady. the rpms go up and down but that is all that happens. what can be causing this? my best guess will be something with a vaccum, but i don't know where to start. let me know what can be going on with this, and if it is safe to drive back to california? thanks, mike.