2003 Chevy Trailblazer sat for 7 years

Got a summer project of a trailblazer that has sat in my driveway for the last 7 years.
I have a general idea of what needs to be done: Fuel drain, oil, brakes, coolant, tires, battery. But could still use some advice.

Flush the brake fluid. Rear differential fluid (but I’m a bit OCD) and transmission fluid as well. sparkplugs and ignition wires. Take a good look around to see if the wiring harness has been nibbled by rodents.

Before you start all this, Pop it in neutral and put a breaker bar on the crankshaft pulley and see if the engine will even turn. After 7 years, it may be stuck. If that is the case, pull all the spark plugs and pour a little automatic transmission fluid in and let it sit. It will help un-stick the rings. Don’t install new spark plugs until you’ve cranked it over enough times to clear the ATF. A buddy had to do this overa few months in a 1959 Pontiac that had sat for over 20 years before it would break free.

The question I think most forum members will have is why has this thing sat for 7 years? The answer may add a few things to the list.

just let it sit after getting a new car, and basically got too busy and forgot about it. While it ran, it had issues with the throttle body, but I gave it a good cleaning, so that shouldn’t be an issue anymore. Car is in great condition with only 70k miles, just never had purpose for using it.

While you mentioned draining the old fuel, you should also flush the lines of the old fuel.
After you get the tank drained and fresh fuel in the tank do the following.
This can be done by removing the line from the fuel rail at the intake manifold, connecting a hose to direct the old fuel into a container, and cycling the key from off to run about ten times.

I think I saw a video lately on-line on a way to drain the tank using the fuel pump itself.

Be sure to remove the intake from the air cleaner to the throttle body, and replace the air cleaner.
This is one place that critters just love to make their homes in.

Yosemite

What’s in the fuel tank can no longer be considered gasoline

Do not be surprised if that nasty stuff has already damaged or destroyed the complete fuel sending unit . . . in other words the pump and the float