Hi I have an 86 z28 305 tip with a t56. When its really hot out and the car is hot it will make a pinging noise like its out of timing in every gear when I punch it out and loses power won't accelerate and it smokes, but at the same time if I don't punch it out it drives fine. What is causing this.

 

If its pinging , the timing is being retarded by the knock sensor. Retarded timing = less power.