I have a 2001 Tribute that vibrates in the front end while excellerating through the gears. It goes away when you let off the gas but comes right back when you press on the gas pedal. I had a garage tell me the transaxel is going bad. I'm wondering if anyone else noticed anything the same or similar. Also, it takes 2-3 tries to start and when it does the engine revs up to 3000rpm's, comes back down and idles rough. It first seems like it wants to stall, then it feels like it wants to lunge. Any help would be great.

 

the vibration may be a bad axle, or maybe one of the axle support bearings - maybe an engine mount broke.
As for the hard starting, try leaving the key in the on position for a second or two before cranking. The fuel pump may be slow to get up to pressure and therefore not start properly. If this fixes the issue, you may have leaking fuel injectors, or a pinhole in the fuel system that is keeping it from holding pressure.

 

Has the IAC (Idle Air Control) valve been replaced?