great little car otherwise, but occasionally won't start after warm engine is turned off. when you turn the key, the S3 flashes and engine turns over but won't go. Sometimes when I run the shifter thru the gears, turn the steering wheel back and forth and yell real loud it starts again, but that might just be a coincidence. always starts again after waiting 15-20 minutes. trans checks out fine. recent tuneup. new fuel pump/filter. I've heard of this problem b4, couldn't find any posts about it here. ??? Can the S3 sensor thing be by-passed?
Thanks
rob

 

i had a similar issue with my civic '92 , and after a couple of months of head ache i found that the main relay had one pin detached partially , so all i had to do was to take the relay out and re-solder that pin , you could barely see that the solder wasn't good so look very closely when you take it out . When the car was getting hot in the summer especially i was getting stuck at gas stations and anywhere on the road because i wasn't getting any fuel .After a few minutes (hours sometimes) it would start again. The main relay is located under the steering wheel at civics and i believe it's the same for integras .Try to pull it out for a visual inspection.
There many other possibilities i'm sure but try this one and let us know if you fix it.

 

ditto on the main relay. been there done that.

also, could be an alternator.