I have a 2000 Hundai Elantra. About once a week, the car would not start. I never broke down in it, but never the less, it won't start about once per week. When the car is running, it is running great with no issues. I sprayed starting fluid to see if it was getting fuel, and it was not getting fuel. It would start for a couple seconds with the starting fluid. I sent it to the shop, and they replaced the fuel pump. He said he checked to make sure the fuel pump was getting electric to it before he replaced the pump. It was. Got it back. It ran good for a week with no starting problems, then I went out to start it in the driveway, and it would not start. Let it sit until the next day, and it started. Let it sit until the day after that, and it would not start. It was not getting fuel, but it was getting spark just like before. Called the tow truck and sent it to the shop, and by the time it got there, it started. The mechanic drove it for three days hoping to get it to not start, but it started every time for him. He went ahead and pulled the computer to look for corrosion, but did not find any. I went and picked it up and drove it for two weeks, and now it won't start again. I replaced the fuel pump relay, but no luck. I suspect it will start tomorrow, but I don't want my wife to get stuck at work with it. I don't know if this helps, but again, it has never broke down on the road. Please help someone.

 

It was the fuel pressure regulator.