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WOT 5k stutter w/ new evo 3 16g

dillon233

Member
Joined
May 20, 2013
Messages
23
Location
Denver, CO
Hey there!

I just installed an Evo III 16g in my gvr4. Everything runs great, boost gauge holds at 15 pounds WOT, but at 5.5k it has a small stutter (engine just looses power, no noticeable sounds or anything) and then pulls slowly. I haven't held it to see if it will go to redline, kinda worried about harming anything. Can't figure out why it is doing this. I cleaned out the TB, checked all connections, seafoamed car, oil change, even switched out the wastegate actuator from my small 16 to see if that was the issue. Still the same problem.

Any help will be appreciated. I will do a boost leak test in the morning and post results.

Thanks!
 

LIV4PSI

Well-known member
Joined
Nov 24, 2011
Messages
1,774
Location
O-H-I-O
Chances are that the boost leak test will answer your question.
 
Last edited:

prove_it

Well-known member
Joined
Jul 3, 2008
Messages
4,201
Location
Sioux Falls, SD
Stock diverter valve could be opening. Like mentioned, do a boost leak test to determine. Start there.
 

G

Staff member
Joined
Feb 24, 2004
Messages
8,896
Location
zompton
What injectors are you running? Stock mas?
 

slugsgomoo

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Joined
Oct 16, 2003
Messages
3,776
Location
Tacoma, WA
Do you have a logger? Since you don't mention other mods, my first inclination goes towards fuel cut.
 

tyeler18

Well-known member
Joined
Jul 16, 2012
Messages
130
Location
Casa Grande, AZ
I agree with possible fuel cut. Have a boost gauge? Could definitely be creeping and fuel cutting, however, that generally feels like a wall. Other possibilities are a boost leak, fouled plugs etc. More than likely a boost leak.
 

dillon233

Member
Joined
May 20, 2013
Messages
23
Location
Denver, CO
Sorry, thought my build would show up on my post. I have a Tial BOV, so not stock diverter. Aftermarket boost gauge holds at 15psi. Running stock injectors and mas. Before turbo upgrade, car ran to 7.5k with no stutter at all. No logger, but my custom EPROM cancels the fuel cut. I have new plugs & wires. Didn't get a chance to boost leak test today, had to replace crush washers on turbo due to coolant leak. Will boost test tomorrow. Thinking I might have messed up with re tightening fmic piping after cleaning intercooler. Thanks for the help so far.
 

LIV4PSI

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Nov 24, 2011
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O-H-I-O
You are running a setup that is wrong. You shouldn't be running a vented "diverter valve" on a stock MAF. Setup this way, your car will never run right, and always make less power than it should.
 
Last edited:

prove_it

Well-known member
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Jul 3, 2008
Messages
4,201
Location
Sioux Falls, SD
What? Are you saying non recirc valves cause a loss in power? How so?

It will die coming to a stop, and run rich during shifts, but a loss of power?

OP:
You mention a chipped ecu. Is it a tuned eprom, or just a fuel cut eliminator? You may also what to try closing the gap on your plugs to .24" and see what happens.
 

LIV4PSI

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Nov 24, 2011
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O-H-I-O
Running rich takes away power, although I understand most people find it to be insignificant. It matters enough to raise your E.T. when racing
 

MX4

Well-known member
Joined
Apr 9, 2001
Messages
780
Location
New Zealand
Do you have stutterbox on your new EPROM? If the speed sensor is faulty you won't be able to rev past the stutterbox rev point
 

Diego

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Joined
Dec 9, 2007
Messages
2,132
Location
In a van down by the river, Iowa
Since you're in Denver, you need to hit up Bryan. His handle is galantvr4559, or I'm not sure if Justin is around on these forums anymore, can't remember his handle.... Jon(Toybreaker) lives in the springs he has a plethora of knowledge and there is GeorgeBillings as well as Mike Texiera the Denver list is pretty big. He ahold of Bryan and take the Galant to Willies garage and they will look it over for you.
They are great guys and have tons of experience and are great help.

Diego
 

dillon233

Member
Joined
May 20, 2013
Messages
23
Location
Denver, CO
I have a recirculated bov, it's not a wrong setup. It doesn't die at a stop or run rich. It's a tuned EPROM.

@Diego, thanks for the info!! I couldn't find too many mmc friendly shops around town. Surprised that there's that many gvr4 guys here. I've only seen one other and it was years ago.

I fixed the problem, the ring clamp on the fmic intake side was a little loose. The boost leak test made the coupling scream like a dying cat.

Thanks for all the help guys! Was faster and kinder responses than forums about my 3kgt. Haha.
 

LIV4PSI

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Nov 24, 2011
Messages
1,774
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O-H-I-O
I'm sorry for the incorrect assumption, I bet 95% of Tial valves are vented. I didn't mean to come off like an asshat
 

jnava

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Apr 18, 2008
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2,073
Location
Arlington, Tx
So boost leak it was.....
 

prove_it

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Jul 3, 2008
Messages
4,201
Location
Sioux Falls, SD
I was wondering what you found on this. Good to hear it was simple!
 
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