4JH5E starting issue

[Chillmark]

Hi everyone! I have a 4JH5E with somewhere between 50 and 70 hours on her. The only way I can start her even in the heat of the Baltimore summer, is to use the glow button for 45 seconds to a minute. I’ve asked around with some people I know and some people say that there is no glow plug up on this engine, and other people says there is. So my question is if there are glow plugs why do I need to use them in the summer? If there aren’t what the heck is going on and why is my engine not starting unless I hit this dead button? Thanks !