my first evo i've had it siting a while due to lil issues but anyway when i first got it i drove it and it only boosted to 10 psi floored. I never had a problem with idle going below 1k and it sounded like it has cams which it doesint(lady who had before said need new tps sensor). now after putting a new bov ams boost controller on it i can only hit 4psi max and it doesint want to idle at all when its warmed up it goes to like 600-800 rpms and shakes like crazy. no idea what the problem is but its only getting worse.s from a cold start idles at 900 and vacuum at -11

 

what bov did you put? Assuming you put an aftermarket one, Evos dont like aftermarket bovs cuz they are not recirculated bov...

 

hks ssqv black edition

 

I guess the first question is did you ever fix the problem with only boosting to 10psi before adding new parts.

Next, if the BOV is VTA, then your idle will fluctuate badly and possibly stall if on a Maf tune. I assume you're on a MAF tune and probably a stock tune.

The last thing is your 4 psi boost limit. You were at 10psi and now you're at 4 psi. How do you know you were at 10 psi to begin with? Do you have a log of boost as well as other things like timing and AFR?

If I were to guess, I'd say there are some boost leaks, the wastegate is not closing during spool up (not enough preload on WG) and the MBC is mounted incorrectly.

Do a boost leak test first then report back. 10 psi and now 4 psi means something is wrong.

 

it was 10 psi before when i just got the car, now started idling badly and i put ams boost controller and the hks ssqv and now i can only hit 3 psi max.
person who had before said needed tune
does it matter if the mbc line is very long?

 

How long is the line? It shouldn't make a noticeable difference.

I think your problem could be the wastegate flapper is not sealing. And/or you have a massive boost leak.

On a separate note, is your HKS BOV recircualted?

 

yep recirculated, and the line is bout 3 ft, do i need a new waste gate then?

 

moved the actuator arm hit 2 step still only 3 psi... not wastegate

 

Are you saying you preloaded the wastegate arm?

You hit the 2 step when the car is not moving. If it was moving and it started cutting out then that's either the rev limiter or boost/fuel cut.

You may have to take off the o2 housing and check to see if the wastegate is sealed when the wastegate is not engaged. Search on here for wastegate sealing problems. Username Sparky has quite a few responses on here about how to check it. I'll see if I can find the thread with vids in it.

 

yeah. yeah moving or not barely any boost... yeah i'll check it out see if thats the prob
thanks

 

I think you're saying that you're revving it out of gear and hitting around 4psi. Are you also hitting 4psi when you're in gear, say 3rd gear and going WOT?

Hitting 4-10psi out of gear is fine. I try to get around 3-5psi with street tires for launch control, but this has to be tuned correctly.

If you're only hitting 4psi during WOT or even part throttle while in gear, then the log is wrong, or if no map sensor, then the boost gauge is wrong, or there is a mechanical problem. Does it feel like you're gettting into boost. 4psi doesn't feel like much.

Definitely check out the flapper!

 

i went wot first and second only hit 5 psi doesint feel as fast as it should be my bro had one. vacuum still at 11 so doesint sound like a boost leak.
only thing i can say is girl who had car before me said she got a new turbo because old one blew the motor is bored out and said it needed a tune.
pretty much it got the **** beat out of it unfortunately.