Just bought the car used,96,000 miles, second day driving it and the check engine light comes on and feels like car is studdering to move till you get it up to about 40.

GET THE TRANSMISSION SERVICED BY REPAIR SHOP

Check codes and report back. Did you buy the car w/the CEL (check engine light on)??

Td

Do you have a tow hitch on your truck? Does it rattle when driving on bumpy roads? I had a truck same year and make when on a certain road the timing would ****** problem traced to knock sensor.

Any service engine light? May be a bad shift solenoid which are located inside the transmission pan.
Check for code(s) and come back with them.

could be a bad sending unit,or if the engine is knocking you have major problems

first off your mechanic sounds like he's taking you for a ride! If the oil lights coming on you need to check your oil pressure. I wouldnt drive this car anymore till I knew for sure I was getting good oil pressure through out the motor. Find a different mechanic! Mechanics are some of the biggest lying thieves! Right up there with lawyers.

have the code read at a partsource or if you have a reader check the trouble code. could be low on transmission oil or its the computer with the factory set parameters on when your next transmission service was due

1984 years came with the 2.0L, 2.6L gasoline and 2.3 diesel engines.

It's most likely a timing belt, but read further for more info. Recommended to be replaced at 60,000 miles (96,000 km) on gasoline engines and on diesel engines at 50,000 miles (80,000 km).

The 2.0 L Engine have two timing belts. One connects the crankshaft and camshaft, the second one drives the right silent shaft.

The 2.6L engine has a timing chain and a silent shaft chain.

Please check to see which particular engine you have and refer to the above for your answer.

Drive it into a dark place, or wait till dark. When it's running poorly, see if you can see any spark flying around. It sounds like plug wires.

put a transmission line cooler on it