I know this is a dumb question but how do you adjust the distributor when setting timing? I have twisted distributors on other cars before but I have a 93 Civic DX and here is what I don't get. The three bolts holding the housing seem to be fixed. They don't seem designed to allow the distributor to slide in order to advance or retard the timing? What do you move to adjust timing? I have checked on Youtube, Google, and even this site. It's almost as if it's so simple people just skip over explaining? I am sure I'm missing something.

 

Loosen all 3 of the bolts with the 12mm heads. The holes are slotted so the whole distributor can rotate once all 3 bolts are loose.

Be sure to put the ECU test jumper in before attempting to set spark timing. In normal run mode (test jumper out) the ECU will vary the timing all over the place as one of its methods to control idle speed. With test jumper in, connect timing light to cylinder 1 and adjust to the center mark of the group of 3 on the crank pulley. You can try the first (frontmost, since the engine rotates counterclockwise) mark but if the engine knocks while driving, go back to the center one.