Idle rpm rate issue

Hi guys,
I'm having an issue with my 95 del sol for a month or so. When I'm in neutral and don't have my foot on the accelerator , the rpm of the vehicle should be pretty much constant. But for some reason the rpm increases to about 1.5-2 for a few seconds and then drops down again without any pressure on the accelerator. I've noticed my mileage drop too.
I'm not sure what the problem is and would appreciate any help or comments.
Thanks a lot

Did anything out of the ordinary happen before this started? It could be dirty fuel. Try some fuel system cleaner.

Thanks for the reply.
I'm not sure if it's dirty fuel. I've filled the tank a couple of times at different gas stations. Want to have an idea as to what the problem could be before I take it to a mech,
Thanks

Hondas do the idle surge thing becuase of all kinda of problems. Fuel, sensors, vacuum leaks, ect. Is your check engine light on by chance?

Nope the check engine light isn't on....which sensors are you talking about?

TPS, MAP, alot of sensors can cause it but if your not getting a check engine light it's most likely not sensor related. It may be your IAC valve. They get stuck open sometimes and cause that problem.

can I check if the problem is actually the IAC valve?..how much does it cost to fix it..or can I do it myself? though I'm limited in my expertise to only doing oil changes, or fixing lights and some minor electrical things.
Thanks

http://honda-tech.com/zerothread?id=1564019

Try that.

Thanks for the info...i'll check it out..
later

lol I just let my car bubble away... my idle hasn't been constant since I bought the car, but then again the motor is modded... is your motor modded? Knowing if the motor is stock or modified can help us help you more effectively. Makes troubleshooting less of a crapshoot and more of a definitive cause/effect ratio