2000 Jeep Laredo 4.7Liter V8 RPMs surge

If the check engine light comes on get the code read...post it here, if no light You may have a vacuum leak, get a can of spray gumout, spray the vac lines and maniflod area, when the idle changes, youve found the leak! You want the engine running and spray on the outside but do direct the stream onto the hoses, if it is a vacuum leak, the engine idle will change speed, then you have detected a leak, repair the vacuum leak and see how it runs!

Check engine light is not on. Checked for vac leak as suggested, none found. Other suggestions?

When was the last full tune up? Fuel and air filters? Clean throttle body? Plugs...