Chevrolet: Car Problems, pontiac grand prix, vacuum leak

Question
I am not sure if you can answer my question or know someone that might be able to help. That includes anyone els who might happen to read this. Please get a hold of me. I drive a 1994 Pontiac Grand Prix. I recently had the thermostat changed. It has about 182,000 miles on it. A while ago I had a refurbished engine put inside it. That was about five years ago. But, my problem now is when I go to start it I have to give it gas everytime. Also, when I come to a stop the engine dies. When I slow down you can tell that it is going to die. It does like it is running low on power almost like a toy. The brake is usually hard and sometimes it doesn't want to turn over. When you try to restart it everything comes back on including the radio, so I believe that it is still getting power from the battery. The last time I changed the alternator was about a year ago. Not much more wore has been done except the trasmission which was about a year ago as well. I will anser an question you may have. I would appreciate any advice you might be able to pass along to me as well. Also, my car as a 3.1 engine inside of it. Thanks for taking the time to read this, I hope someone can help me.

Thank You!!!

Answer
Hi Kyle,there are so many things that can cause those symptoms, have you car hooked up to a analizer to see if there are any sensors failing, this will save you money in the long run by not replacing unnecessary sensors, also have the mechanic look for a vacuum leak. I hope this helps you if you need more info just let me know. Regards, Keith.