[coupe]

Drive car everyday and no problems, until now...

After car has warmed up, there's a pinging under acceleration (from 1/4-throttle up) and it seems to have started with the cool weather a few weeks ago. I pulled timing back 14º, then 12, then 10...now it's 9º and not better. I also have played with fuel-pressure, but no help. Then I suspected the C&L meter, so I took the cold-air-kit elbow off and just mounted the filter on the end of meter...no better. Then I changed the electronics in the C&L...no better. I put in new plugs...no better. Car is fine under normal driving, but step on it a little, especially under a load like 3rd or 4th gear, and it sounds like I have 87-octane gas...I have tried some other gas stations too and nothing helps.

Here's the kicker: When car is still fairly cold in morning, I cannot get it to do it...runs strong and pulls smooth..once it gets up to operating temp...it does the knock/ping.

Only other thing I changed around the time it started doing this is the electric fan. Could there be a problem with not enough airflow over the aluminum heads? The fan keeps water temp way cool in traffic but maybe it's not doing enough airflow...
Or could it maybe be the fuel-pump is going south (again) and the preignition is just a lean knock?

My only other guesses would be a bad TFI? or distributor?

I have always fixed troublesome things like this with timing adjustments, better gas, plugs, cap/rotor, etc.. but It's not working. Feedback please.