Hi i have an astra g 2.2 16v coupe (z22se) a month ago approximately the engine started to fail, whrn turning the key the engine took a little longer to turn on and when it was turned off,but i turn the key again and it stays on, stable rpm, everything ok, only fails to start the first time in cold or after 6-8 h without use. i found one video in youtube from other guy, my car do the same
https://www.youtube.com/watch?v=UABdt5VOfZY