This car has set in a grage for 9 years

You have too much fluid in the transmission. Park on level ground. After a 15 min drive. Leave engine running. Set parking brake. Transmssion in neutral. Check tranny fluid. A cup or more over will cause this. Better to have less than too much. Drain at least a full 1 leter bottle. Go for drive check it again. As above.

If it keeps happining check your fluid and if its low every time u have a leak somewhere.

Sounds like the oil level in the gearbox is low ,if it has a dipstick then start engine and chock wheels ,put in reverse with engine running and check oil level

Are you able to drive it in 1st gear? Is it just not catching 2nd, 3rd or 4th?

Try putting the transmission in low or 1st gear manually shift it down and try taking off as you accelerate shift it manually to 2 then drive. Did it take off like it should when you put it into low and then shift up or did you feel more power when it was in low if so it sounds like the transmission is not going into low gear but taking off in maybe second gear or even drive. When it takes off in any other gear but low it will start slow and sluggish and as you begain to gain speed it will start feel normal but thats because the speed matches the gear you in at that point.If my assistance was helpful please take the time to rate my assistance thank you.

sounds like you are low on fluid if not then it's time for AAMCO to take a look

Take it to a major parts store and they can hook up a scan tool and tell you what is wrong. Most do this for free.

Heavy tools needed:
-Floor Jack
-Jack stands
-wheel chuck

Hand tools needed:
-3/8" drive ratchet
-12 mm deep socket (a 6" extension isn't shown but also recommended)
-1/2" drive breaker bar
-1/2" drive 10" extension
-1 1/16" deep socket
-1/2" drive 24 mm short socket
-oil catch can
-funnel

Steps:
1)Put the wheel chuck behind your back tire and Pull up your e-brake

2)Find floor jack position

3)Lift car until you can fit jackstands under the car
4)Lower the car a bit so that it sits flat on the jack stands and the floor jack still has a bit of pressure pushing up on the mount

5)Locate the reverse sensor in your engine and unplug the grey connector on it.

6)Right behind it is a 12 mm bolt you have to remove. Use the deep socket 12 mm, extension and ratchet to remove it and just move the metal braket aside a bit.

7)Now use the 1 1/16" deep socket to remove the reverse sensor.

8 )Now get under the car and locate the drain plug.

9)Use the 24 mm socket and the 1/2" drive breaker bar (if your socket is 1/2" drive) and loosen/remove this bolt. This WILL be messy so make sure you have your oil catch can under neath it.
Try to hold the bolt in place as the fluid comes out until a good bit has drained. This will prevent it from going everywhere. Just let it drain for about 5 minutes.

10)When it's done draining, replace the drain plug and tighten a good bit. It has an aluminum washer so it'll feel like it can keep tightening but just go until you feel it's very snug.

11)Lift your car off the jack stands and lower the car back down. Remove the oil catch can prior to doing this.

12)With car on the ground, grab your funnel and place it in the hole where the reverse sensor would go.

13)Add 2.5 quarts of your desired gear oil. You can use Redline MT90, Amsoil 75W/90 gear oil,...Just make sure it's GL4 compliant

14)Replace reverse sensor and tighten. Again, this also has an aluminum washer so just tighten it until it feels nice and snug. RECONNECT THE GREY PLUG!

15)Replace the 12 mm bolt and just hand tighten until snug.

16)Prior to starting the car, push the clutch in and move through the gears slowly. You should notice a nice, smooth gear transition.

17)Last, clean up, remove wheel chuck from rear tires, and go take it for a spin.

Enjoy!

Check and make sure that you have the correct amount of tranny fluid. If so one way to find out if it's the tranny is to disconnect the linkage at the transmission and put it in gear there. If it works normal that way you know it's the linkage and not the tranny.

If this has an automatic transmission check the fluid to see if it is low of burnt. Fill if necessary. If not unfortunately you need to take to a transmission shop so it has a warranty when repaired.