My 1995 Mercury van has been parked for 3 years. It was having transmission problems and I didn't have the money to get it repaired at the time. I want to get the transmission fixed but I need to get it running first. What should I do before trying to start the engine?

 

Change the oil for sure.

Make sure you have a good battery and air filter.

If it's had gas in it for that long, drain it and put fresh gas in it with a bottle of Stybil in it.

 

Better make sure before rushing it down to the tranny shop that seals are not dried out in the engine, after you get it running for a while (if you do), and start leaking. Also, hope engine cranks over without loud click, meaning probably engine locked up from lack of oil. There is a product, in case, that you can put down in plug holes to help free that condtion. I have a stored pickup that used to start and run strong and I too neglected to start it regularly and now it makes a real loud click (even when battery charger was on it for long time, then set to "boost" setting) and my next step will be to pull plugs, try to see if I can even turn the engine at all by hand, put chemical down in the holes if need be, and try to see if I can't rotate engine by hand THEN before hitting the key.