The greatest Automotive Mystery that still is not answered. I had a base 1991 Chevrolet Caprice that used to lose power intermittently. The engine used to make a popping sound, and the loss of power came and went. I took it to three GM dealerships,two said they found nothing wrong, and one said they never heard of the problem. I have owned and driven many cars since then, but this automotive enigma has always haunted me. Anybody ever heard or know about this? Car Talk and Top Gear Guy
And you don’t think it was back-firing through the intake manifold because an intake valve was intermittently hanging open (or, the other causes of backfire)?