Is there any miss fire while driving or at idle? Is the rpm needle moving up and down by itself? My suggestion is to clean the iac valve, throttle body, and clean the egr valve.
Check to see if your spark plugs are properly gapped. Also check to see the condtion of your fuel injectors.
After you have done all this, try getting a bottle of "Sean Foam" at AutoZone, and believe me this stuff is great!!!
I'm assuming you did everything needed for a tuneup on a 94 camry
-spark plugs
-wires
-pcv valve
-distributor cap
-igntion rotor
-air filter
Everythings perfect and not a bad sin days