have been trouble shooting this for a while now since my 93 si has become a second car it was not a big deal to fix it right away. The car would intermittently not start, checked main relay was okay and working, tested fuel pressure and it was okay and I had spark. I thought bad fuel pump but could hear it prime even when the no start condition was happening. Once the car was running never had it shut off on me. I finnaly got a chance to hit the pick and pull this spring and thought for 20 bucks why not pick up a used pump. Well I installed it today and wouldnt you know it the car started right up and ran like a top. The old pump must have been going out and was not able to build enough pressure to start the car but once running was able to produce enough to keep it going. First time I have seen one go out like this.

 

Hmm thats crazy. I think I got something like that going on with my car.

 

Did you replace the fuel filter as well? A plugged fuel filter will show good pressure, but the flow volume won`t be there. A plugged filter will also cause more stress on the fuel pump causing it to fail.