hey folks, need your assistance
rebuilt the engine recently, done some miles for brake-in and now I'm begining to tune the car. flashed standart 96530706 v7 rom (which I used for brake-in period too)with its fairly rich fuel and mild ignition tables and went for logging. car missfires like crazy after ~7-8 psi, shakes and won't go, so bad that I had to lift off the throttle

spark plugs are brand new BPR8ES gapped to .027, I'm also running COP setup, so don't think that the missfire is due to ignition system, especially on such a low boost/rpm
afr leans out when it starts to miss. I'm not a pro and can't catch the moment wether it missfires due to lean afr or first it starts missfiring and then wideband registers lean mixture due to unburnt oxygen

general specs of the car: 2.3 forged, S2 cams with springs/rets, 10.5 turbo, megan O2+downpipe + 3" catless exhaust, hardwired wallbro 255, 560 injectors, 93 octane fuel. boost is on actuator pressure yet, so doesn't go above 10-ish psi

the zip file is attached with logs of 2, 3 and 4 gear pulls. any assistance is greatly appritatted guys

 

try gapping your plugs down to .022-.023

 

can 7-8 psi blow out the spark on new pugs and COP ? wierd...

 

I would suggest gapping the plugs down to .022" as suggested and see if that cures the hiccup...

 

your gap is pretty big. what the other members said try .022

 

+1

Try a smaller gap, see if it helps.

 

today pulled the plugs to check what's there going on. haven't had feeler gauge at that moment, will try and reduce gap as soon as possible
no signs of det but the porcelain is pretty white (lean ?) also timing seems too high ? would like to hear suggestions

sorry for the cell phone pics










image upload

 

so

1. gapped plugs to .022
2. tried another spark plugs (BPR8EIX)
3. tried another set of COP
4. tried oem coils
5. tried another fpr
6. tried another MAF

problem remains the same

what to do ? anybody viewed my logs or rom, maby it's down to tune ?

 

I have just checked your logs. What AFR are you running? In your logs I can see WideBandAF column, what's that? If it is your actual AFR, then it's obvious, why your engine is knocking.

 

its not knocking, it missfires. can't determine actual afr, during spoolup up to 7-ish psi it richens out from 13 to 11.8 and after ~7psi it missfires and the wideban sees unburnt mixture as air. I explain it so, correct me if I'm wrong. thats why it shows lean when it starts to miss the spark

an yes, WideBandAF is actual afr from my LC1

 

I made my comment after I checked your logs. Have you tried to make 11.5-11 AFR just after spool up???

 

I've richened up whole map above 100 load by 0.5 point and dropped a degree of timing but no luck, still the same

 

Maybe it wasn't enough... Anyway it looks lean for me before misfires as well.

 

Edited

 

it was bloody engine bey fuel filter