RPM accelerating after stopping and take off slow what's wrong?

Check the comment box, I posted in the wrong spot.

fuel filter or pump

Not driving a corvette? Just kidding. More details are important. How slow is your acceleration? Is it 0-60 in 8 seconds, or 20 seconds? What is redline on your car? If redline is 5K then 4000 is a good responsible shift point. If redline is 8K then shifting at 4000 is probably robbing your engine of it's torque and horsepower band. I believe the GTS model has an 8K RPM redline, the GT may be lower, but in that case, shifting at 4K is too soon for strong acceleration. Your Tachometer should have redline clearly marked. For responsible use, stay below that, maybe 10-20%. For economy stay further still, but for power you need to let the engine use it's RPMS, especially smaller and fewer cylinder engines usually don't make their power until they are half way through the RPM range and above.

Plugs ,wires,coils.

How is it you have the issues & the dealer never drives it,
to experience the same thing you are?

They are jerking you & don't care to resolve

Either leave it there,try a different dealer or have the
factory rep come & work on it

Hi Richard, I'm not an expert on Jags, just a little jealous I don't have one. Looks like a very nice vehicle. Have a close look, inspecting all hoses and vacuum pipes on the intake manifold side of the engine for any damage or loose fitting. The problem seems to be a leakage of air which is raising the idle speed. Regards John

Sounds like you should not be driving the vehicle at all until the issue is rectified.

get computer codes but sounds like low fuel pressure (fuel pump)

If you replace the throttle body,
Check the accelerator cable for correct installtion.
if correct.
Replace the accelerator cable

let me know

for better help with this go to mpvclub.com there are a great bunch of guys there, with ALOT of expertise.