I recently changed the fuel pump and the thermastate and the egr on my 2000 mustang v6 3.8 but now the car has slow acceleration and just a loss of horsepower why?

Brother Dave, stuff wears out as you well know. But indications don't always point to the obvious. I know it sounds like fuel delivery problem, and new pump didn't fixit, so change the EGR valve. That's Exhaust Gas Recirculation valve. It's part of emissions control and only a couple of small bolts hold it onto the intake manifold with a small vacuum line running to it. A bad EGR will cause the slow pickup speed and won't pull a hill or even a short grade. I believe this EGR change will fix your situation completely. Good day my friend, and happy motoring.

Why would you expect any fluids to help ?

Have you changed the fuel & air filter,spark plugs,
cleaned the maf sensor,changed the two front O2
sensors & checked fuel pressure?

When that is done,check for codes,then vacuum
leaks

If it is over ten years old, the exhaust converter may
be blocked

Last check for cylinder misfires as those ignition
coils fail a lot & several at once

Don't over look the egr valve

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.

Mine was doing that also.. We changed the two EGR valves, changed spark plugs and wires, and finally cleaned the Mass Air flow Sensor with carburetor cleaner. That seemed to helped the most. You have to take the sensor off to do it.. you can find a youtube video that explains it. Now all I have to do is figure out why my car's RPM's surge when slowing down.

egr will only affect running at idle or slow speeds.under acceleration it can indicate poor tune-up components or even a partially plugged fuel filter not allowing enough fuel,or even a weak pump.a bad tps(throttle position sensor) can also act the same way,usually it will set a code,but not always.if it has a(maf) mass air flow sensor on this system it can cause the poor acceleration,again usually, but not always, will set a code in the computer.

Clean/Change air filter, fuel filter, air filter, turbo filter. Clean and check EGR valve and Turbo gate. Check the hdi fuel pressure. Open the injectors and clean it. Give it a try and may be you can save 600 euros.

how I change the EGR valve assist switch for toyota camry 2000

Just change the air flow meter.Thats faulty.

change the fuel pump relay.