Vacuum leak?

This sounds like a vacuum leak. However, we need to start with checking for codes.

Here is a guide that will help with getting OBD I codes:

https://www.2carpros.com/articles/toyota-trouble-code-definitions-and-code-gathering-method-1990-1995

This is the process on how to check for vacuum leaks. Please run through this info and let us know what you find.

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Below you will find a chart on spark plug issues. We need to check this and pull the plugs and see if they are fouled. This could be a misfire or just worn spark plugs.

Please let us know what questions you have and what you find. Thanks