hey guys for the past few days ive been reading countless treads on this issue. cant seem to pin point the problem. around 4th to 5th at 5500 rpm ill experience this sputtering. my list is as followed.

fp red 80mm ported
ams inter cooler
injen piping system
880 injectors
synapse bov
aquamist meh kit
ams 3" exhaust (cat delete)
map performance 02 housing
walbro 255 pump
ngk iridium 2 step colder (gapped at .22)
kelford 272 cam
exedy hyper twin heavy duty clutch

my evo 9 is set up for 29.5 psi. you know i really didnt notice this issue till i installed on my new synapse bov. i did read that loosening the bov spring could help so i did and now its a lil smooth through 4th but is still sputters in 5th..maybe not as much but it still there. any help?

 

Sounds like spark blowout. Make sure the car isnt overboosting. The old BOV could have been leaking and with the new BOV you could be seeing higher boost levels. Coils could also be getting weak.

 

i had my stock bov on for a few days before getting my synapse. im surprised the stock bov helded up during pulls but none the less it did. i was looking into that ams 2 ch ignition system.

 

Ok I changed out my plugs, gapped them and swapped out my battery for a optima red top so I go out for a cruise and decide to see if the sputtering had gone away. I punch it in 5th hitting over 80mph and I get loud back fire and the evo went no more. I had to coast off the freeway and she began running sluggish. She was sounding like a badly tuned Honda and couldnt gain speed after that. I had to call a tow truck at 1am. Sucks. You guys have any insight to this?

 

check your IC pipes possably blew one off would cause a loud bang and then car would maybe idle and not much more.

 

^^^ what this guy said, to remedy the problem, when you get home start from off the turbo on the ic piping, spray some hairspray on the piping, hopefully if your boosting that high you have t-bolt clamps, spray coupler clamp tighten boom, go to each one till your at the throttle body give the hairspray like 30 seconds after you put the coupler on the piping then tighten it down and youll be good to go.

 

thanks guys for the info. i will check all the piping. and ya im using t bolt clamps

 

You shouldnt do 5th gear pulls unless its because you ran out of 4th.....

 

dearly noted.

 

Check the cam sensor. Something similar happened to me. I swapped my car's cam sensor with a friend of mine and it worked fine.

 

another thing to check too since your boostin so high, is possibly throtle body seals unless been replaced, and check your injector seals for cracking....

 

Check plugs/plug gap.

 

thanks guys, i will check all that as soon as i get to her. i needed to take 1-step back and breathe...