A couple times since I've got the car I've had problems starting it. It will either start for half a second then shut off or just not start just keepin turning over. I'll wait 30 seconds then it will start right up. This isn't happening every time I try to start it but a few time since I bought it. I've had it about a month. Its just had a tune-up. I was wondering if you guys would know what would be causing this. This may be a coincidence but the tank was around a quarter empty both times it happened.

 

Probably related to fuel; it is common for Civics to take a little longer when starting with a low fuel level because the fuel pump cannot prime the lines fast enough. Has this ever happened with a full tank?

I wouldn't worry about it unless it starts happening often or it leaves you stranded somewhere.

 

same problem i used to have. i am about 95% sure its gonna be your main relay. same thing used to happen to me. turn the car on and it would die about a sec later. next time it happens turn the key to the on position and listen for the fuel pump prime then turn off. if u don't hear it , its your main relay. by the way main relay is located above and a little behind your trunk lever

 

what did you replace in said 'tune up'?