, it's possible the inconsistency lies with your pump. My first machine was a gaggia coffee and it never pulled two consecutive shots consistently. You are probably hitting the 30 sec. target with a coarser grind because your pump is putting out less than 9 bar, which is not unusual in a machine of that quality. I would suggest you focus more on what is required to get the most out of your current setup and enjoy it for a while, regardless of what the settings are. If, after that, it still isn't meeting your needs, you can either save up and get a better espresso machine, or live with what you have and when you need a better espresso, head for the local coffee shop.
"cheaper pump machine"