I have a 4 cyl 00 contour auto and just starting having a few probs with it. Here are the probs. 'd appreciate any advice you guys can give me. I'm lost

1. The engine idles high and sometimes goes up and down. The brake booster hose broke and i jerry rigged it to work for now. I'm assuming maybe a vacuum leak there?

2. When you try to rev the engine from idle it seems like it is only going up to about 4k and it acts as if it is bouncing off of the rev limiter(up and down rpms real fast). Also the engine shakes around in the bay horribly and makes a loud growling noise. Also when you try to drive it , it won't get out of its own way and only goes to like 25 mph unless you really push it. Checked the timing belt and it is good but could it maybe skipped time? Is there anything else you guys can help me with this prob. I just replaced this engine because i thought it was internal and i got a low mileage unit and i still have the same prob! Please help any way you can. Thanks a lot!!