I'm helping out a friend. She has a 1990 Civic CX (D15B2) and we sold it to her. We put a new head on it two years ago. Two weeks ago it started to run rough once in a while. Then it stopped running yesterday, but we got it back running today. No cels are being thrown. Sometimes it will start and run like any normal motor and sometimes it will run like garbage and when you give it gas it will bogg out and stall. The only things I can think of are fuel dilevery and change the plugs, wires and dizzy cap. Have any ideas?