Have had a lot of toyotas, and I have decided to keep and build this 85. Normally I buy built trucks and fix then then wheel them then go off and sell them. But I got this stock 85 for real cheap. It has 196,000 miles, passed smog first try, changed the oil a month ago, I check it every morning am the level stays the same and the color barely changes. This is a strong running motor, one of the strongest I've seen or had. But one day it started running really rough and I have no idea what it could be. At idle it runs almost like it's misfiring every time, or running rich, but when I drive down the road, it is fine like nothing has happened. Any idea what this could possibly be? (Spark plugs new cap n rotor new wires new fuel lines, fuel pump, fuel filters, all that good ˟˟˟˟. I have no idea why it's running so rough. Any ideas? Thank you!

 

TPS? AFM? Any codes?

 

No codes or anything like that.