Hi guys this is my first post, i have a 1989 Rx7 GTU with 170k miles, i’ve bought it recently and am learning about rotaries as i go. Ive been having an issue where when i cold start the car, not always, but sometimes the car pings very loudly every 2 or 3 seconds, which i’m guessing is detonation. I have to hold the rpms at 2k for a minute to two for it to idle normally and not ping anymore. And it doesn’t happen if the car is already warm or if i start it the same day. Is this an issue anyone’s seen before or could maybe help point me in the right direction? I’m thinking maybe it’s leaky injectors or something with the ignition. Any help would be appreciated, Thanks

 

you might want to post a video, this is something that requires a bit more than a description to help with. you'd also likely need a mechanics stethescope to do some hunting for the noise, as it is unlikely preignition.