So I have a 98' Honda Accord Lx, 5-speed, 4-cylinders, with vtec. I had this problem where sometimes it would start and then other times it wouldn't, it would turnover but just wouldn't catch. I changed out the main relay because I was told that that could be the issue. Now there is a new main relay, the car starts every time but then turns off seconds after. With the old main relay in when it started it wouldn't turn off , so why would this be happening with a new relay? What else should I look int that could be the problem?

 

I remember there being a recall on ignition switches, but I think that was for like '94-'97 models. Still though, maybe something you'll want to check.

And check the main relay connector for pin fit, corrosion, etc.