First off you need to do more diagnosis and give us a little more to go on than just "no power". It could be hundereds of different things. Do you get power every time you start the car and then it goes wimpy after it warms up? Is it getting worse and the power never returned?

Replace your filters.

I don't know how the tank is plumed on the inside. If you reverse the lines you might suck air, but either way it should blow out the screen a little. Sounds like a good way to get out of being stuck on the side of the road. Another diagnostic is the coke bottle trick. Secure a gatorade bottle or something like that in your engine compartment and run the fuel lines into it. You might need some extra 5/16" feul line. Use that as a temporary fuel tank just to see how it runs.

People replace those injector return lines with clear fuel lines to see if there's air in the fuel and to try to track it down. Keep an eye on them to see if fuel leaks out while idling (replace), or if air is leaking in from elsewhere. Sounds like this car was having problems before you bought it.

Your temp guage will peg if the wire is grounded. Check the wire. You need a temp guage if your driving cross country. If you can't get it to work put in an after market temp guage. I got one for $20 at O'rieley's.

The turbo is an expensive part and it almost never fails. Check to see it the ALDA has been jacked with. Pull out the air filter and see how it runs. If you still suspect the turbo pull off the U-shaped intake tube and see how it runs. This is for diagnosis only. With the tube off rev the engine you should see the impeller (compressor wheel) spinning. You may need a mirror and a flashlight and an extra hand. There's almost always oil in there.

If everything still check out. Bypass the lift pump with your coke bottle.

Still no power. Your valves or IP may be out of adjustment. Or you could have clogged exhaust, open the headers. I suspect the IP, but there's no way to tell from here. This is one of the most expensive parts, so check every other possible thing first.