[scotsman60]

Steve,


Thankx for your reply. I'm aware of the potential seriousness of the pinging and I didn't mean to appear flippant, however from discussion on the Rennlist board it appears that pinging in 964's and 993's is fairly common in California in hot weather.

The car has a standard chip and has 74,000 miles.

Today the temperature has dropped to around 60 (from 90) and I have no pinging whatsoever. I have located a gas station (76) that sells 100 octane gas and I plan to mix five gallons into the next full tank - probably tonight. Of course, I'll need to wait for hotter weather to know if it really makes a difference...

If the problem goes away by increasing the octane I will try and figure out what mixture I need and may also try octane boosters - do you have any experience with octane boosters? Can you recommend one? Any issues with octane boosters?


I'm still suspicious of my knock sensors. As far as I can tell the DME can retard the timing by up to 9 degrees in response to knock sensor signals. If it's still pinging at this point I should get an engine warning light but I'm not.



Doug