1988 Nissan 300ZX Pinging in hot weather.

some of these fuel mixes can make it ping if you have fuel that you got out of a pump that is 15% ethanol don' t use that in that car. Use only 10% max your car is not set up for the higher blend of alcohol. you might see if your egr valve is clogged or partially clogged as well as the passages. and if it continues back your timing off or go to premium fuel.

Don't know what an egr valve is. My mechanics have been with this car for twenty-six years and they don't have an answer. What I guess I'm really asking is is there a relationship between ambient temperature and pinging? Because I don't know what else has changed. I buy my gas where I always buy my gas etc. The hotter it is outside the worse the ping.

the egr can be either on intake or exhaust manifold so check there ambient temp can effect the pinging the hotter it is outside the more it will ping. also check for a vacuum leak as your egr is vacuum operated