ok so im in the process of tuning my 06 evo and seem to keep having the same problem...whenever i do a 3rd gear WOT log from 2000rpm to redline i get a sputter or cut at around 2800-3000 rpm and then again at around 3800-4000 rpm...same with when im cruising at 55mph then downshift to 3rd or 4th gear and floor it, throttle tip in on acceleration seems to sputter until after peak boost...only modifications are injen intake w/ intercooler pipes, turbo xs TBE no cat with the stock boost levels, boost cut table is set at 290 load...A/F ratios are logged at 12.8-12.3 spool up...11.6-11.8 peak boost tapering down to 11.4 by redline...timing at peak boost is 4-3 degrees...has anyone had this same problem? could it have something to do with lean spool?...

 

Sounds like a spark plug issue.
1. How old are you plugs, and are they still the stockers?
2. Is this your first tune since the added parts?
3. You can find a really good write up on lean spool here on the forum, a lot of guys suggest to diable it. I did on my 03 VIII, and AFR dropped about a point.
Hope this helps..

 

how your boost numbers look like?

 

yes this is the first tune since the added parts have been installed...when i put my cat back on it doesnt sputter but with no cat it sputters so im wondering if the test pipe is creating a lean problem that i can't seem to find

 

check your plug gap. make it nice and tight, like .025" almost certainly thats the issues. also, if you turned lean spool off, make sure the turn on and turn off points are not the same. that can cause some nasty hessitiation problems. i usually give it 500rpm difference.

 

also, if you turned lean spool off, make sure the turn on and turn off points are not the same. that can cause some nasty hessitiation problems. i usually give it 500rpm difference.[/QUOTE]

can you elaborate on this concept... This is the first I have heard of this. I have mine set (both) 2500 as directed.

TIA

 

^if your car drives smooth from 2000-7000 you don't have the problem. i beleive it is related to certain roms. its a pretty horrible miss though. you'd definately know if it effects you.

 

Sounds like your spark plug. if it has not be replaced yet change that out first and gap it.(IX values are Standard value: 0.5 − 0.6 mm (0.020 − 0.024 inch)) I'd go closer to 0.020 if you are running high boosts.

 

Kevin, please expand, preferably in the lean spool thread. Also I've posted a question there concerning viewing lean spool as RPM instead of 80/224.

https://www.evolutionm.net/forums/ec...ummies-18.html

 

so i checked my plug gap and they were all at a good .25 gap...but then i looked a little closer and found the hairline crack in the ceramic...replaced all the plugs and car runs great

 

Good deal glad we could help you out. If you are in the boost a lot, you may want to make plug changes a routine, like every 3,000 miles. I use the NGKs they are fairly inexpensive and widley avalible.