lonertic Posted December 14, 2009 Share Posted December 14, 2009 hi guys, I'm quite new to the forum as I've only just bought my car recently...for the last few weeks I've been reading posts and soaking it up like a good little sponge and searching where possible but I still havent found my answer, sorry to annoy everyone if this is already covered.. my car's shaking quite rough at exactly 1300-1400rpm range when in neutral on driveway (off load) and if I maintain that rev range, it usually results in knock sum ticking up pretty quickly (+1 every 1 or 2 seconds)...smooth above or below that range.. don't notice it under normal acceleration coz it goes past that RPM range pretty quickly.. not sure if its related, but after normal (or hard) acceleration, whenever I let go of the gas pedal to drop to cruising speed, theres a good chance of knock sum goes +1.... not always, but 60 to 70% of the time..last few datalogs shows this can happen anywhere, eg: 3600 or 4200rpm...during a normal 15 minute drive, knock sum will be 34+ and start counting from 0 again - doubt this is normal or healthy for the car but I'd be happy to be told otherwise.. p.s. running on 98 octane, stock map on A2UG001G rom if it helps.. thx heaps everyone, any help is appreciated.. Link to comment Share on other sites More sharing options...
Ridgeracer Posted December 14, 2009 Share Posted December 14, 2009 Maybe you have a misfire in one of your cylinders. Check your connectors to the coil packs are secure and they all have the little spring inside that touches the tip of the spark plugs. Also check the connectors on your injectors. Have you tried to log cylinder roughness? "Gimme mines Balboa...Gimme mines".....Clubber Lang - Mr. T Link to comment Share on other sites More sharing options...
lonertic Posted December 15, 2009 Author Share Posted December 15, 2009 thanks Ridgeracer, see log attached - i've had to trim it down because it was logged over an hour+ driving and the log was 30,000 lines. there WAS some misfire in Cyl 1 and 4 - i was actually expecting more on Cyl 4 because that seems to be a common weakness in these cars, but it had only 1 misfire, or 5 misfires across 500ms however you interpret it...but alot more misfires on cyl 1... even so, that works out to be misfiring 0.005% of the time which is probably acceptable... logs show that most misfires are when the car's practically at idle (0kph), and one where it was rolling at 75kph in neutral (low RPM again).. yet if i hold the rev at 1300rpm, car will consistently vibrate without fail... and knock sum is quite high at low RPMs...anyone experienced knocks without load or might know what could b wrong? (on several separate WOT logs there are no knocks even at max req torque in S#).. I'm baffled...romraiderlog_20091215_083203_trimmed.csv Link to comment Share on other sites More sharing options...
RJS5689 Posted December 15, 2009 Share Posted December 15, 2009 I'm having a similar issue. Did you use an Access Port to do your data logging? Link to comment Share on other sites More sharing options...
dvran Posted December 15, 2009 Share Posted December 15, 2009 +1 on checking if the coil packs are seated. You have to press on them real hard till you hear them click seated. You might want to change the plugs to see if that's an issue. $12 for plugs is worth it. Link to comment Share on other sites More sharing options...
lonertic Posted December 15, 2009 Author Share Posted December 15, 2009 RJS5689 - I used Tactrix OP2.0 and RomRaider logging (with latest defs)... dvran/ridgeracer - I'll get the plugs done next service since my dealer's extending my warranty by another 2 yrs and 50kkms as long as i get them to service my car but guys, which spark plug should I use? also, some people have run one step colder plugs than stock? any reasons? Link to comment Share on other sites More sharing options...
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