problem with pinging detonation noise when accelrating

[my1990300zx]

I filled it up with premium and a booster of ethanol but it still has the pinging detonation rattling sound when accelerating. Could this be timing I have high idle also.

1990 300zx na

[Taleek]

Do you have access to a timing light? I'd give that a try to see where its at. Is the engine completely stock, or is there an aftermarket tune, or bigger injectors? Basically anything that could change up your air/fuel ratio as well. What is you're idle normally at? Also do you have an automatic or manual transmission?

[Taleek]

Also check the self diagnostics and see if you can pull any codes from it. I can better help you if you can do that

[DCaff300ZX]

Due to having a 1990 model (old style injectors and their issues) and high idle combination, most likely your issues lie within the injector system (injectors themselves failing which is common, or connector corrosion) which will take some testing and maintenance work...and may well not fix the problem but be necessary to move to any further issues.
Remove the connectors carefully and inspect for green corrosion, clean and replace them if broken. You also need to ohm the injectors looking for about 15.2 ohms, anything else and you have a bad injector. As they fail it puts more stress on the rest of the system to keep up causing the high idle, but which can also be from other things so worry about that later after injectors are fixed/tested OK.

And definitely check for codes as Taleek suggested!