Just did a search and did not come up with anything on what the cause of a fluctuating cruise control might be from.
It engages and disengages fine but even on a road with slight I mean slight hills it really drops mph and then has to catch up to the desired mph. It really does not stay constant at all, or is the civic cruise that bogus??
Any help is appreciated

 

i would cheak the cable make sure its not getting stuck

 

Yes check the cable and see if its not loose or binding.
If neither is the case, replace the unit.

 

You need to mention what car you have.