Losing boost about 5k??? Help??

[BluEvo]

so yesterday after leaving the Import Cafe, i was taking off and i notice that i was losing boost about 5k. it boosts fine from 3k-5k, but drops drastically with the sound of leaking air at the higher rpm. i read the post about tightening the lower bolt of the dv/bov but that didn't help. i checked all the lines and made sure they were all tight. :?
my car was running fine before. no major mods, just a catback, and grounding kit. help on this....anyone???

now that i tightened all the bolts down, i'm wondering if my stock dv/bov is leaking itself or defective. maybe it's not holding. damn, i need get a boost gauge. gonna get it next saturday. should i bring it in to the dealership or hold off until i get the boost gauge installed to see if i have a definate boost leak?

[EvolvedDSM]

A quick boost leak test is what you need ;) Double check all your clamps and physically grab each hose/coupler and give it a good shake. The BOV is a possibility--check the vacuum line running from it back to the intake manifold.

[BluEvo]

thanks man, i'll re-check those clamps/ hoses again and give it another run.

is there anyone who has brought the evo in because of a defective factory bov? i know there has been many complaints, that it doesn't hold boost very well in the first place. do they even warranty the bov if you claim it's not holding boost properly?!

[SouthernCrane]

so yesterday after leaving the Import Cafe, i was taking off and i notice that i was losing boost about 5k. it boosts fine from 3k-5k, but drops drastically with the sound of leaking air at the higher rpm. i read the post about tightening the lower bolt of the dv/bov but that didn't help. i checked all the lines and made sure they were all tight. :?
my car was running fine before. no major mods, just a catback, and grounding kit. help on this....anyone???

now that i tightened all the bolts down, i'm wondering if my stock dv/bov is leaking itself or defective. maybe it's not holding. damn, i need get a boost gauge. gonna get it next saturday. should i bring it in to the dealership or hold off until i get the boost gauge installed to see if i have a definate boost leak?

maybe you might want to take it to the dealership before you install the boost gauge, otherwise they might blame it for the car's malfunction. that's just to be on the safe side........you never know what might go down at the dealership.

[AlwayzEVOlving]

Stock EVO's taper off boost after 5k RPM.....maybe you are feeling that. Get a flash or boost controller to get rid of it....I did and my EVO feels like it should have from the factory.

my .02

[wicked1]

My stock BOV leaked consistantly under long boost runs. The dealership offered to replace it but I declined on the offer. Go get yourself an aftermarket BOV. The good thing is the dealership will still warranty your car but not your blow off valve.

[GReddy_917]

I personally drove Terrence's car and trust me...it is NOT running the stock boost level...it feels like around 12psi on WOT....very unusual.

Terrrence, I would take it to Mitsubishi before you get the boost guage.

Oh ya...and I hightly doubt its a blown stock BOV.

[EvoVIII]

thats sounds about right, if your car got a boost leak, it drop about 5psi then usual

[AlwayzEVOlving]

I personally drove Terrence's car and trust me...it is NOT running the stock boost level...it feels like around 12psi on WOT....very unusual.

Terrrence, I would take it to Mitsubishi before you get the boost guage.

Oh ya...and its not the stock BOV.

OIC.....I agree 100% get it looked at before you install a boost gauge...Mitsubishi warranty would love an easy excuse to decline free warranty repair. So greddy917 is he running a stock or aftermarket BOV?

[GReddy_917]

no major mods, just a catback, and grounding kit.

[AlwayzEVOlving]

[quote="GReddy_917"]I personally drove Terrence's car and trust me...it is NOT running the stock boost level...it feels like around 12psi on WOT....very unusual.

Terrrence, I would take it to Mitsubishi before you get the boost guage.

Oh ya...and its not the stock BOV.

did you read your ORIGINAL post???? that's why I asked.

[BluEvo]

so this is what i did tonite when i got home from work. i took the bov out, and inspected it. to see if it was cracked or anything unusual like that. nothing. so i re-installed it and checked all my lines to see if they were snug and tight. everything was cool. i took it out for a wot test run and i did feel a difference than before. boost was kickin in pretty well. only to find that it find that about 5500 it tappered off and that sound of air leaking was there again.
got back home disconnected the battery for about an hour to reset the ecu. then re-connected and did another test. same thing. it pulls hard. and about 5500 to redline. it drops and theres that air leaking sound again. well i was hoping to resolve the issue by checking all my lines, re-tightening my bolts/screws, and resetting the ecu, but no luck. i guess it's time to bring my Evo in to the dealer.
thanks for everyones input. i just didn't want to have to hassel with the dealership. i'll post the outcome of this mystery later.......to be cont'd....

[EvolvedDSM]

It definitely sounds like a boost leak. It may be one of your couplers was damaged, but still manages to seal at low levels. Once the airflow/boost increases to a certain point, it can no longer hold the seal and escapes.

[GReddy_917]

It definitely sounds like a boost leak. It may be one of your couplers was damaged, but still manages to seal at low levels. Once the airflow/boost increases to a certain point, it can no longer hold the seal and escapes.

Exactly what I was thinking. :buds:

[EvolvedDSM]

The best $10 you can spend: http://www.vfaq.com/mods/ICtester.html

[gaughtboost]

terrance, it sounds that you may have a crack or a slit somewhere in the vac lines. replace those or swap urs out w/ someone to test yours. that could eliminate another cause.

[BluEvo]

so i made an appointment to bring in the Evo to Capital Mitsu on Saturday to have them check out the prob. Wish me luck guys.... :paranoid:

[SouthernCrane]

so i made an appointment to bring in the Evo to Capital Mitsu on Saturday to have them check out the prob. Wish me luck guys.... :paranoid:

Good Luck

[EvoVIII]

damn, is it me or is it you? today was hella hot, my Boost started droping like :jawdrop: took longer then usual to get to 20psi and it doesn't hold for long... then drop to like 16psi WTF!!!!!!!! my boost usually stays around 21to19, not 20to16

[Frissby]

so i made an appointment to bring in the Evo to Capital Mitsu on Saturday to have them check out the prob. Wish me luck guys.... :paranoid:

Let me know what the dealership says, I have a Greddy boost controller and I peak at about 22 or 23 psi., but at 5000 it drops off to about 10 psi., then at 5500 it drops off to about 5 psi., which I know is not supposed to happen. I also have a SES light on with a "Random Misfire" code so it might have something to do with that, but I am reluctant to take it to the dealership because of the boost gauge and controller. Thanks.

[nebolic]

so i made an appointment to bring in the Evo to Capital Mitsu on Saturday to have them check out the prob. Wish me luck guys.... :paranoid:

Let me know what the dealership says, I have a Greddy boost controller and I peak at about 22 or 23 psi., but at 5000 it drops off to about 10 psi., then at 5500 it drops off to about 5 psi., which I know is not supposed to happen. I also have a SES light on with a "Random Misfire" code so it might have something to do with that, but I am reluctant to take it to the dealership because of the boost gauge and controller. Thanks.

do you feel lost of power? It could be your boost gauge being incorrect. Otherwise it looks like the ECu thinks your over boosting?

Nebo

[BluEvo]

sent PM

[EvoVIII]

so is there still boostdrop on ur car BlueEvo? did they fix it?

[BluEvo]

Made a 2nd visivt to Mitsu and they found nothing. Even with the tech ride-along. We found nothing. It never happened again?! It was the strangest thing. I put on the GFB right after the visit to Mitsu and have not had that issue since.

[thomas]

wow, thats weird :?

well at least its not acting funny anymore...quick question, did you have gas in your car when you were boosting?

'cause a similar problem happened to me when i tried to boost WOT on a near empty tank, safety mechanism came on and i couldnt boost more than 10psi. misfire, i think...no not misfiring system, but misfire... :wink: sorry couldnt resist, initial D, haha.

juss wondering if you had gas...nm. hope everything works out, terrence.

[BluEvo]

wow, thats weird :? well at least its not acting funny anymore...quick question, did you have gas in your car when you were boosting?
juss wondering if you had gas...nm. hope everything works out, terrence.
Yo T, yeah i had plenty of gas when that was going on. Heres the catch though. Mr. Nebo and I switched out my stock bov with his GFB and i ran the car with no boost issues. So we figured that might be it. I then took it to Mitsu (2nd trip there) a couple days later cause it was going it again. They found nothing so I installed my GFB that same day and no probs. :)

[EvoVIII]

thats great, now u can kick ass with ur Evo again :thumbsup:

[BluEvo]

thats great, now u can kick ass with ur Evo again :thumbsup:hey thanks man!

[Frissby]

so i made an appointment to bring in the Evo to Capital Mitsu on Saturday to have them check out the prob. Wish me luck guys.... :paranoid:

Let me know what the dealership says, I have a Greddy boost controller and I peak at about 22 or 23 psi., but at 5000 it drops off to about 10 psi., then at 5500 it drops off to about 5 psi., which I know is not supposed to happen. I also have a SES light on with a "Random Misfire" code so it might have something to do with that, but I am reluctant to take it to the dealership because of the boost gauge and controller. Thanks.

do you feel lost of power? It could be your boost gauge being incorrect. Otherwise it looks like the ECu thinks your over boosting?

Nebo

I do feel a huge loss of power when I lose that boost, so I know it's not the gauge. I also don't think the loss of boost is the same problem as the SES P0300 code, which also is creating driveability problems, so I'm afu'd. I called Vishnu this morning and am just waiting to hear back from Shiv, I think I am just going to yank the boost controller and get a Vishnu flash. Anyone wanna buy a Greddy Profec B Spec II electronic boost controller, cheap?

[PK@WORKS]

The Greddy Profec is a decent boost controller... if you take the time to set it properly. With two of us (one driving and one making adjustments) we can usually dial it in within 2 hours. (We can perform on-the-fly boost pressure datalogging)
If you are looking for a stealthy, clean flash which absolutely holds boost through proper ECU remapping, then of course we recommend the WORKS P2 Flash.