Nasty vibration on the floor under the gas pedal

Hello,

If problem only occurs 'under power' sounds like a u-joint (driveline - rear wheel drive) or a cv-axle (front wheel drive). Check for excessive play, fluid, boot tear and breakage.

Check your spark plugs.

ENGINE HESITATES WHILE ACCELERATION
LOSS OF ACCELERATION

It can be fuel pressure issue or it's the problem with accelerator pedal or its clogged filters causing there.
There are many other possibilities. I suggest you to go through the list of help links mentioned below, these will help you to confirm where the actual fault lies: -------
Jerks and Hesitates During Acceleration?
http://technoanswers.blogspot.in/2012/07/2004-dodge-town-country-jerks-and.html
-----------
Loss of acceleration?
http://technoanswers.blogspot.in/2012/02/loss-of-acceleration.html
---------
Headlights flickering and car hesitates to start?
http://howtobyme.blogspot.in/2012/02/headlights-flickering-and-car-hesitates.html
--------
How exactly the Vehicles Accelerator Cable works?
http://repairhelpcenter.blogspot.com/2011/11/how-exactly-vehicles-accelerator-cable.html
-------------
How exactly Vehicles Accelerator Pump Diaphragm Works?
http://repairhelpcenter.blogspot.com/2011/11/how-exactly-vehicles-accelerator-pump.html
--------
2000 Toyota Avalon: Engine Lean Codes and Knock Sound on Acceleration?
http://whatisbyme.blogspot.in/2012/05/2000-toyota-avalon-engine-lean-codes.html
---------
2004 Toyota Avensis: Acceleration And Deceleration makes noise on Front End?
http://whatisbyme.blogspot.in/2012/05/2004-toyota-avensis-acceleration-and.html
---------
Wheel hop under hard acceleration?
http://technoanswers.blogspot.in/2012/04/wheel-hop-under-hard-acceleration.html
--------
2009 Chevy impala accelerator pedal sensor?
http://technoanswers.blogspot.in/2012/02/2009-chevy-impala-accelerator-pedal.html
---------
Nissan Pathfinder stalls and bucks on Acceleration?
http://technoanswers.blogspot.in/2012/02/nissan-pathfinder-stalls-and-bucks-on.html
--------
Acceleration lag problem?
http://repairhelpcenter.blogspot.com/2012/01/acceleration-lag-problem.html
-------------
These details will help.
Thanks.

ENGINE HESITATES WHILE ACCELERATION

LOSS OF ACCELERATION

It can be fuel pressure issue or it's the problem with accelerator pedal or its clogged filters causing there.

There are many other possibilities. I suggest you to go through the list of help links mentioned below, these will help you to confirm where the actual fault lies: -------

Jerks and Hesitates During Acceleration?

http://technoanswers.blogspot.in/2012/07/2004-dodge-town-country-jerks-and.html

-----------

Loss of acceleration?

http://technoanswers.blogspot.in/2012/02/loss-of-acceleration.html

---------

Headlights flickering and car hesitates to start?

http://howtobyme.blogspot.in/2012/02/headlights-flickering-and-car-hesitates.html

--------

How exactly the Vehicles Accelerator Cable works?

http://repairhelpcenter.blogspot.com/2011/11/how-exactly-vehicles-accelerator-cable.html

-------------

How exactly Vehicles Accelerator Pump Diaphragm Works?

http://repairhelpcenter.blogspot.com/2011/11/how-exactly-vehicles-accelerator-pump.html

--------

2000 Toyota Avalon: Engine Lean Codes and Knock Sound on Acceleration?

http://whatisbyme.blogspot.in/2012/05/2000-toyota-avalon-engine-lean-codes.html

---------

2004 Toyota Avensis: Acceleration And Deceleration makes noise on Front End?

http://whatisbyme.blogspot.in/2012/05/2004-toyota-avensis-acceleration-and.html

---------

Wheel hop under hard acceleration?

http://technoanswers.blogspot.in/2012/04/wheel-hop-under-hard-acceleration.html

--------

2009 Chevy impala accelerator pedal sensor?

http://technoanswers.blogspot.in/2012/02/2009-chevy-impala-accelerator-pedal.html

---------

Nissan Pathfinder stalls and bucks on Acceleration?

http://technoanswers.blogspot.in/2012/02/nissan-pathfinder-stalls-and-bucks-on.html

--------

Acceleration lag problem?

http://repairhelpcenter.blogspot.com/2012/01/acceleration-lag-problem.html

-------------

These details will help.

Thanks.

bad tire, gad wheel bearings , loose steering tie rod ball joints , wheel alignment
take it to a front end specialist for a full inspection

it could be a bad engine or transmission mount.

How about motor mounts.

It may be the transmission input shaft bushing or bearing, located in the rear of the engine crankshaft, in front of the clutch assembly. If the bushing or bearing is dry (needs to be greased), the input shaft will still try to turn with the engine rpm, even though the clutch pedal is depressed. Also, the clutch disc may not be fully releasing, which could possibly be corrected by adjusting the clutch pedal linkage. good luck

THE CLICKING NOISE IS THE SHIFTER LOCK RELEASING, NOTHING TO DO WITH BRAKE LITES. CHECK FOR GOOD GROUNDS AT REAR LIGHT SOCKETS.

I would venture to say your exhaust is hitting your frame, or, you may need new motor mounts. The exhaust is what I would lean toward. If you can imagine your exhaust sitting under your vehicle, and the fact that the vehicle has a little age, the motor mounts probably give a little, causing the motor to move slightly on acceleration and deceleration, thus your exhaust is going to move, and may be vibrating on whatever its touching. Good luck.