I know this has been discussed many times, I have searched. Here goes anyway.
My 94 DX civic idles rough, also anytime I let off the gas(like going down hill) when I get back on the gas it sputters, going up hills it sometimes loses power and sputters. Stop at a ligt, it suptters on take-off. At highway speed 55-80 it runs great.
One other thing a couple of weeks ago I saw a link on HT that showed a picture of a d15b engine showing the fitv, ect. If anyone could repost that link. It is getting about 30-33mpg, but I think it should get more? No codes, no check engine light.

 

How is your timing?

 

when the engine is cool get a can of carb and choke cleaner and spray it agount the areas like TB, intake .... places that it can suck air into the combusion camber .... dont spray a lot .... a little will do ..... if there is a air leak .... the rpms will change since ... carb and choke cleaner is flamible.

if you dont find any leaks .... check all vacume hoses pinching each one to see it it has cracks.... if you pinch hard enough you may seal the vacum leak and the engine may smooth out if it does it is a bad hose.....

if that doesnt work ..... check your spark plugs .... if they are fouled out .... clean your O2 sensor ...

if none of that works ...... check timing .....

good luck

 

When was the last time you replaced your fuel filter and plugs/wires?