Engine Mechanical problem
1990 Toyota 4Runner 4 cyl Four Wheel Drive Manual 215456 miles
----------------------------------------------------------------
when i am at a stop light, the engine would reve up and down like its trying to breathe. it would drop below 1000rpm but wont die. when the ac is one...i hardly does it. also it seems like i cant tell how hot my truck is getting. sometimes the termoniter would work and some days it doesnt. Some one told me that it might be a trottle body or even a air flow meter. it worries me that some day its gunna die on me. can you help??