Need help
 

My blazer starts but will shut right off and this only happens during the day when it's hot out. I've changed the thermostat cuz it was melted closed and it helped for awhile and now it's started up again. Also it use to be when you kept your foot on the gas it'd stay on but now as soon as you take your foot off it immediately cuts off. Please someone help me out.

Thanks.

Check codes etc. With what you gave it sounds like a possible idle air control valve issue. Also heat changes resistance and can effect failing sensors and poor wires and connections.

How do I do all this? I'm sorry I know nothing about cars or how to fix them but my boyfriend is a quick learner if it's easy to fix

Go to Autozone or other store and have codes read from the computer. If you can't get it there borrow a code reader from someone or use the loan a tool at a store that does that. First step is see what the computer tells you.

OK we will do that thank you