Removing fuel injectors

OK, I often need to juice the gas when I'm starting the car when it's warm. I replaced the filter and that seemed to help but it still happens every other time. It also seems my thermostat is toast so I'll be replacing that today, but I wanted to check the injectors. After I removed the bolt-on cover (and relieved the fuel pressure) I couldn't get the injectors out for the life of me! It was like there was a vacuum at the other end holding them in. I pried with a screwdriver until the red plastic started to contort and I tried twisting and shaking and I got nowhere. Tried on cyl 1,2 and 4 and all with the same result.

Am I missing something?

Thanks for any and all input!

Brad