periodic engine rev

[big-nate]

recently the engine in my 2001 wrangler sport started revving up a few hundred RPMs every 20-30 seconds. its not such a big deal on the dry roads but on the ice its enough to make the tires spin and lose traction. does anyone know what the problem is?

 

[Bounty__Hunter]

Sounds like a vacuum leak.

 

[drewbuddy]

At first I thought a vacuum leak somewhere, but I find it weird it's doing it and you're tires lose traction. Is it when accelerating or when throttle is held at a constant? Does it do anything else abnormal? when slowing down or speeding up? In park and give it a steady higher idle? Does it start good? You ever smell fuel? Know if your getting spark? how do spark plugs look? Any trouble lights light up? These are questions that came to mind. I would start with vacuum hoses for corrosion, no seal condition and confirm spark and condition of plugs , is some things you can just eyeball