ignition coil! check that the two wires are connected properly, I think I had the same issue as you, I did some maintenance and then the car wouldn't run for more than a second or two every couple start attempts, because I had accident pulled out one of the coil power wires, it sorta ran because it was arcing from the connecter to the terminal. and like General Kartheif said, there's always codes, try a engine running code test if you can get it to run long enough, they usually put out a different set of codes if you can manage to do the test. if not.... verify everything's connected and sending and receiving power. seems like your issue resides in the roots of the ignition system.
Also a ground coming from your computer connection on ECU, if it's not connected you won't get codes