Hi, I have been battling with this problem for some time (as Martin knows -dmc UK) but i wanted to know if anyone else has experienced this problem and offer some suggestions. A brief run down of the situation is that i have a supercharged engine with EFI. The car hadn't ran for 10+ years before these installations. When i had it on the Dyno it started to ping VERY violently at around 4000rpm so we had to shut it down. I had some custom cerimac extractors fitted and i noticed that the ceraminc coating had discoloured on cyclinders 1 & 2 only. (free flowing with no tight bends etc) After the engine has warmed up at a high idle number one and two extractors are around 300+ deg c while the rest are around 180 deg c hense the reason for the discolouring and i presume the high tepms are causing the pinging. Injectors and rails have been checked and appear to be operational. The EFI computer side/timing etc has been checked by the software engineer and appear to be normal. I have also changed the plugs for new ones with a number 6 heat range. If everything was hot or lean or one complete bank or something then i could understand but i have reached a stand still! I have been advised by Martin that the cam timing on cyc 1,2,3 bank is 2deg advanced from the factory which could be concidered as a small factor if all three were running hot. Any suggestions ? ? Cheers, Nick Australia To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/dmcnews/join (Yahoo! ID required) <*> To change settings via email: mailto:dmcnews-digest@xxxxxxxxxxxxxxx mailto:dmcnews-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/