I HAVE 2001 JAGUAR S-TYPE 3.0 IT STARTS BUT WHEN YOU SHIFT THE GEAR TO DRIVE, IT MOVES BUT WHEN YOU STEP ON THE GAS PEDAL IT DOES NOT ACCELERATE. WHAT MIGHT BE THE PROBLEM?

Transmission needs rebuild

its trying to fly

Did you or someone else try to replace the transmission fluid?

Check your trans fluid. Look in the Owner's Manual to see if you have the shift interlock override/bypass button available. This allows the shift lever to be moved w/out pushing the brake pedal.
ENSURE THE PARKING BRAKE IS SET before trying this.

If it moves w/the shift interlock disengaged, it's likely an issue w/the shifter - not the transmission, but since it's a Jag....well, you're probably going to have to sell a kidney!GL,Td

A variance of 20 PSI indicates a problem.

first you must change with the newer oil and filter shift than check up again if the problem persist than need to change the pressure disc inside the shift boxes remember there are to chamber to change oil , the oil must be dextron 3 AFT

It could be several things : cable and / shifter need adjustment., manual shift valve is defective or ECU may be defective. I recommend having a transmission repair shop diagnosis the vehicle and do the repair accordingly. This could be fustrating and expensive if you don't get it right yourself.

when has the last time you had a trans serv. done on it? if you take it to a shop the will tell you that you need a rebuild. thrid gear and over drive are about burned up.

This model has a tranny computor under the dash on the right side screwed to the bottom of the dash. If I remember correctly, there is also an inline fuse attached to the harness. Check the fuse.

replace your transmission as. your clutches have burned and, the cost of repair would be prohibitive.