Need help w/ '88
 

The engine is a 4 cyl, and that's about all I know. It might be a 2.0 or a 1.8. It has a Carter one barrel with manual choke. It was hard to keep running last fall, Now it's impossible. The temp gauge doesn't get out of the cold range, and I have changed the theromstat. Hoses are a little warm and the water pump does work.
I can eventually get it started, but the engine will not rev up at all and it sounds like it is running on two cylinders. I changed the plugs, wires, cap, and rotor. Didn't help a bit. Going to try some dry gas tomorrow. Anyone have any other suggestions?
I also need a complete air cleaner assembly. The carb is 3 1/4 inches OD. I would be willing to buy a new air cleaner assembly, but cannot find one anywhere I also need a timing belt shroud.
Any suggestions or parts would be sincerely appreciated.
I love my money, but.....................
Also, can anyone tell me where to find the numbers to determine what engine this is? I do not think it is the original.
Thank you. Rannug