Sport light starts blinking

This is your transmission control unit telling you there is a problem. I have another post here (http://www.fixya.com/cars/t5554380-92_honda_accord_d4_light_flashing) with details on how to diagnose. This link says "flashing D4 light" but the issues it the same. 90-91 accords have flashing S lights for TCU errors, and 92-93 have flashing D4 lights.

Click the link for an explanation of your problem and the solution. http://autorepair.about.com/library/a/1i/bl809i.htm

the alterator relay is not ingageing you need to have it replace see when it cool down it started back up the relay became un hooked dont for get to diconect the batteri cables first hope this helps

try looking at the ECM.

you might want to check your air/fuel mixture. It might be not be getting proper air intake.

THE S LIGHT BLINKING ON THE DASH STANDS FOR SPORT NOT SERVICE IF YOU LOOK ON YOUR SHIFTER YOU HAVE A LITTLE BUTTON IF YOU PRESS THE BUTTON YOUR CAR WILL DRIVE ON SPORT IF YOU REASEASE THE THE BUTTON YOUR CAR SHOULD DRIVE REGULAR.
I hope this helps
Sam

does it shift through it's gears? 1st ,2nd,3rd? if it dosn't then the tcu is burned out a common problem for 91-93 accords

The s light might mean a problem with the transmission computer it is right next to the computer for the car under the carpet. does the car shift gears? if it don't the tcu is burned out ,it is a common problem for 91-93 accords

Last year in the summer of 2007 I had the same problem with my 1991 Accord dx. I replaced the Transmission Control Unit (TCU) and the light went out and the car has been driving fine every since.

possibly due to low trans fluid pressure. the cooler in the radiator may be plugged. to check, disconnect and bypass cooler with rubber line & clamps. drive 2-3 miles. shifting OK now? install auxillary cooler to bypass one in radiator. you can get one at auto-zone $30-$50. may just need fluid & filter change, but more likely it's the cooler. when they get plugged, either one, pressure drops alot.