I purchased a 2004 Gen 2 for $600

I'm in same state as you... Let me know how I can help? If I were in your situation, I'd be super excited about this opportunity and I'd replace the 12volt and set up a charge and balance on hybrid battery.

Once that is done, I'd start it up and see what kind of error codes it has and proceed accordingly...

 

Congratulation, a barn find of a relatively late model vehicle. Be aware, low milage doesn't mean as new, a motor that virtually never stops will last a lot longer than a rarely used one .... sitting for a long time is also very hard on them if they haven't been prepared through the "layed up vehicle" process.
My advice as a motor mechanic with over 40 yrs in the trade.
Replace all the fluids, petrol and petrol filter and fingers cross the pump hasn't gummed up.
A new genuine Toyota hybrid battery isn't that expensive, the expensive part is letting the Toyota workshop install it. There are enough You Tube videos to guide you every step of the way, use an anti corrosive anti dis-similar metals paste on every link and wire connection on the battery, I can highly recommend a product called Alminox, not that expensive and the extra work will pay big time when it comes to trouble free battery life.

After the engine has run for a day or two, change the oil and oil filter again. The reason is, a lot of moisture will have built up in the engine and a lot of accumulated junk will have flaked away and ended up in the new oil, you don't want to be running that crap around the lubricating system.
Be prepared that you might end up changing all the light bulbs, I'd recommend replacing them with LED units as they fail, or just bite the bullet and start at one end and progressively go around the vehicle and swap them out. You can keep the old ones for spares, that way you'll never need them .

Looking forward to what you find and how good the vehicle is once you get it on the road. Give the tyres a really good inspection, looking for cracked tyre walls and cracks in the tread, you don't want one of those to let go on the way down the highway.

T1 Terry

 

At this point time isore important than miles. Suck gas tank near dry . You can pull thru electric pump . Won't hurt a thing . Add new gas . Let er rip . This is kinda how I get em . 500 to a thousand .

 

If you know anyone that has a good spare HV battery you can borrow for testing, install it, along with a new 12v battery (or disconnect the old one and use a jumper pack). Put a new battery in the FOB, or put it in the key slot and try to start it. I wouldn't think twice about initially trying it with the 3 year old gas in it. Modern gas isn't the same as the 70's. It's been in a very well sealed tank, not sitting in a 5 gallon bucket in the backyard. If it starts, great. If not, then look at seeing if you need to drain and refill the tank. Once you prove it runs, figure out which way you want to go with the HV battery. New would be best and would provide you with a bullet-proof car for the next 10 years, other than typical other issues that may pop up.

 

That's right. Good power from the hybrid battery is the only way to start the gas engine.

Swapping a few modules is probably the cheapest way to get a shot at it. That's about all Green Bean does; you can save a bundle doing it yourself.

 

Nice.

Cars don't like to sit for years though.

I second getting rid of as much of the gas as you can, and refill with a premium grade (detergent additives) fuel.

Both batteries probably won't take to the long-term lack of use. You've saved a lot in buying the car, I guess it's time for a new-ish HV battery.

Change the oil with the high mileage oil (with the additives that are made to try to treat the seals and gaskets). You should probably get it running for a bit, then change out all the fluids you can.

 

I think newPriusBatteries.com would be a good choice. It was started by a battery expert here. You would end up with a battery better than new.

 

there are many threads here on battery reconditioning if you are interested

 

Build Hybrid Battery Maintenance Gear For Under $100 | PriusChat

 

About 5 years ago, I purchased a 1972 Torino with a 351C that had been sitting in a yard, untouched for over 8 years. Had a tow company drag it onto a flat bed and deliver it to my house. I installed a good 12v, checked the oil, shot some starter fluid into the carb and had the wife crank it. Fired up in about 3 seconds and was rough as heck. I kept spraying starter fluid into it to keep it running and after about 30 seconds? Smoothed out and ran just fine. Started and ran it for an hour-ish every day for about 2 weeks while cleaning it up, and then sold it for 10x what I paid. I've bought dozens of cars that have sat for multiple years, and NEVER had to drain and refill a fuel tank due to "old" gas. "Old" does not mean "bad or contaminated". A gen 2 Prius fuel tank is sealed much better than most. It doesn't make sense to try to drain a full tank of fuel without at least trying to just start it.

 

I used to buy sub $1000 cars and some of them are dead, some do start, run but don't drive for some reason.. it turned out it cost me a lot so the saying "a cheap ANY_CAR_HERE is an expensive one". You could get lucky sometimes and as a lesson for me, I prefer to have it running and driving even though I have to pay higher..
For the Prius, it might be a diamond in the rough but at it's state a $600 (fair price anyway for non-running) gamble and you have to be resourceful to keep cost down. First the engine will not run without the hybrid battery in working condition, that means you have to deal with the hybrid battery first. You could buy modules (not cells!) from 2ndlife and replace them individually (cheaper route) or buy a refurb for $1000 (greenbean or Greentec) You should try grid charging it first, Venice Hybrid sells charger or you could build your own for around $100. At that mileage engine might be ok but to be safe change the oil and filter. Since it's been sitting for years, tires are probably shot as well as the rotors and suspension bushings. The shocks might be ok but I expect them to leak once you're able to drive them around.. Check for rodents inside the engine bay, that will be your worst nightmare if something electrical were chewed.. what's the reason anyway why it's garaged for 3yrs?

 

If it were mine(and I would have been all over tis sort of deal) I would try to limit costs to get it started. Spending 3K on this car as is just to get it to run is a bad investment. Spending a couple hundred is better especially if there are more issues than planned. Did you get the gas gage to read out? A full tank would be better than partial but with the rubber bladder that is not as critical. Three years for gas is not terrible, siphon a bit out of the tank into a pickle jar or something and try using it in a lawn mower. I have had 10 year old gas start an engine, not recommended but again limit money out. The bigger issue is how brittle the rubber bladder might be. They can be a real pain to fill when this happens and a replacement is very expensive. If a 12V battery got the computer booted and lights on the dash that is great. See if there is a local Prius battery "rebuilder" and talk to them. They might be willing to put a charge on yours if you pull and deliver it. Or build a charger and do it yourself. Please share your journey, very interesting.