Greetings

Recently I had the water pump change but  afterward, the car has a hard time starting, battery check out good,  usually in the morning it would start well

but when I got back to restart it an hour later it would have a harder time starting.

Before changing the water pump I never had a problem starting so I also change the spark plugs and air filter but it still has a hard time starting. 

I took it to another mechanic and he mentioned that it  might be the fuel injectors

but would have to do a test to be sure. Have you ever experienced a problem like this? I live in Los Angeles California 

Can you refer me to a good reasonable mechanic 🙁 ?

Joseph