Idling problem with my 94 civic

Ive been having an idling problem with my 94 civic ex. For a while Ive noticed that when I drive my car when its not warmed up, and Im
idling, the rpms increase and then decrease for about 5-6 seconds. Then after my cars warmed up, the idle fluctuation stops.
However, now my car seems to be idle-fluctuating when my car is warmed up, but its a little less suttle, but its still fluctuating. What is the cause of this? Anything serious?
Posted using the interface, at author's request
Articles individually checked for conformance to usenet standards
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file
Upload is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.