MembersPage/MarcSwanson/FirmwareBugs

It has been discovered that a knock channel setting of 168 decimal in vemstune can result in spark angle being *added to* relative to the main spark map. This occured on a 2.7t engine running vems 1.1.88. See the .vemslog here:

http://www.efiexpress.com/downloads/v3.3_n003146-2011.06.07-12.22.44.vemslog

note where the engine hits 1.3 bar boost, the spark map requests approximately 14 degrees ignition timing, however the spark angle reading in the log reports over 25 degrees. This resulted in burnt pistons on 2 cylinders (and a junk engine block) on the customer motor. No knock settings imaginable should result in knock timing increasing over base values, naturally...

I see two misconfigurations in your config:

1) 168 means 10101000, but probably you want 00010101 which is 21 decimal. But it not lead to fatal behaviour - it just maps which sensor corresponds to which spark event.

2) guilty setting most probably is threshold for mean value. It must be higher than 100% for sure. 300...500% in fact. Now code is in black area - it should do something if noise is lower than actual noise.

3) logging is configured for indivudual power, not for knock so we do not see what knock ctrl really do.

But I am agree - no knock settings, even wrong, must not lead to advancing. GintsK?