2G Feels like boost leak should Boost come from BOV vacuum line

[2ggst1998]

So my gst has been having problems with stuttering under hard boost, i got the codes read and they r p0505 and p1103. Also under the car theres a sensor with two vacuum lines disconnected. These r the ones thanks

 

[Priority DSM]

Boost control solenoid lines?

If not connected to the sensor they need to be capped off and/or routed to the boost/vacuum source they are looking for.

The Reason these are disconnected you ask? Manual boost controller installed, running waste gate as boost control, or Shoddy workmanship on a R/R job.

It's an easy fix. If you need the line routing info you can look up the info for boost controller vacuum lines and add/subtract connection until your match the diagram.

If you are running a MB controller already...what are you boosting at? If you boost too much psi over stock without supporting mods you will see weird things happen.

 

[2ggst1998]

I want to remove the mbc for now because it came with it. I want to remove everything bring it to good running order than put it back on, is there a thread to remove an mbc. Also would any of the codes cause the stutter under boost, or is it just a boost leak, ill get a vid up soon. The mbc is running under extremely low boost like its almost completely untwisted.

 

[Priority DSM]

I want to remove the mbc for now because it came with it. I want to remove everything bring it to good running order than put it back on, is there a thread to remove an mbc. Also would any of the codes cause the stutter under boost, or is it just a boost leak, ill get a vid up soon. The mbc is running under extremely low boost like its almost completely untwisted.

Sorry I don't know the codes by heart. I didn't search for them either.

Look up diagram for boost control solenoid for your DSM. Should be easy to remove the MBC and put the lines back to the stock solenoid...if you want to go back to stock.

 

[2ggst1998]

Ok thanks but can a stutter under hard boost only be caused by a boost leak? It boosts fine until 4500 ish than it starts to bog and stutter.

 

[J'sDSM2]

The codes point to an ISC (idle system control) malfunction and a waste gate leak. Is your waste gate correct? Does your car idle rough? Connect all hoses and check the turbos waste gate for leaks. I have not watched it but you can check your ISC. Follow this link for more info-

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http://www.dsmtalk.com/forums/showthread.php?t=87845
http://engine-codes.com/p1103_mitsubishi.html

The stuttering can be caused by fuel cut if you do not have a stock turbo or boost way over stock (7 pounds) boost on a T-25 turbo but leaks can cause similar problems.

What modifications are done to your car? You should put that on your profile.

 

[2ggst1998]

Ya sorry ill get my profile running properly and get my mods up there. I have greddy intercooler piping greddy intake and greddy bov and a mbc. At first i was hitting fuel cut because my mbc was at a high boost level. But i turned it way down. Now its throwing these two codes and it hesitates under hatd boost at around 4500 rpm. Like i was telling priority dsm. Im going to disconnect the mbc and hookup the boost solenoid properly and see what happens. Ill come back and let ya know.

 

[J'sDSM2]

Ok cool. Good luck

I have stuttering because my intercooler is damaged so I have a leak before it reaches the throttle body.

 

[2ggst1998]

ok so update, i removed the mbc and attached the wastegate solenoid properly. when i was driving the vacuum line that went to the intake from the bov came off. while it was off i was able to rev to the red limit with no problem. when i hook the line back together it stutters at around 5000 again. whats going on here?

r the vacuum lines connected wrong?

Anyone?

Im going to have to rule the boost leak suggestion out right. Because when the vacuum line from the bov to the intake falls off the car revs totally fine and can hit the red limit, once i plug it back in it has the bogging amd sputtering problem at around 4500. Is this a bad bov or what?

 

[J'sDSM2]

If you still have check engine codes, you should address those.

How does the car idle?

You shouldn't have lines falling off because if the bov line comes off, it's technically a boost leak.

 

[2ggst1998]

I do its just the idle malfunction code, i hooked the boost solenoid back in and took the mbc off, but since that the vacum line from the bov wants to pop off when i floor it. And when it does i can rev fine all the way to red limit, but once its plugged back in it has the bogging and almost like fuel cut at around 4500

 

[J'sDSM2]

How does your car idle?

Well, you should get some hose clamps as well as inspect the bov. Is the bov stock or aftermarket? If it's aftermarket, what brand is it? You should not have vacuum lines popping off when you reach 7 lbs of boost.

Cheap aftermarket bov's have a very thin diaphragm and expensive ones should have a stronger one. Either way, an adjustment screw is important to adjust.

Are you referring to the recirculation hose or the small vacuum hose off the bov nipple?

 

[2ggst1998]

It idles perfect when the hose is on, the bov is a greddy. And i thought it was a fake greddy but after inspecting its a real greddy. Also its the small vacum line that is coneected to the bov nipple. Ya i ziptied the hose on.

When that little hose used to pop off the idle would go to shit, but the car hot the redline which confuses me

 

[J'sDSM2]

I would take off the bov and look at it because it might be old. Check the diaphragm to make sure it's not torn, weak, or broken in another way.

NGR makes a great replacement bov for Greddy. I own one and know that it's great.

If the car idles bad, it's not going to have the proper air readings to reach high rpms like it's suppose to. You may not experience the studded on the top end when the idle is wrong but that doesn't mean the car is tuned right. It could have poor performance on the high end compared to if the idle was right.

 

[2ggst1998]

But i feels like fuel cut when the hose is on. Would a bad bov do this?

 

[J'sDSM2]

I'm not an expert but over the last 5 years of owning the same car I can say you never know. There are a lot of variables and the cars computer can do a lot of the work for you. The cars computer is able to handle all the engine management including air, ignition and fuel.

Yes a bad bov shooting into the air could possibly cause the symptoms. The car idles wrong so it may be getting more air than needed. Once it hits the high rps, the air escaping through the bov or coming through the new recirculation path on the intake (after the maf sensor) it is able to run alright.

 

[2ggst1998]

Could my wastegate be too tight. What would cause a fuel cut like scenario?

 

[J'sDSM2]

I don't know about your wastegate being too tight. It would be nice if you had a boost gauge.

If your car is reading the air that's in the car wrong but still controlling the car, you could have fuel cut. Your car thinks it has a certain air, fuel, and spark but really has a different air, fuel, and spark.

Your car is idling poorly so it clearly has the timing or something off. You need to fix the ISC before you race.

You may be right with the waste gate too. Did you follow one of the diagrams to put the waste gate correct? Maybe the waste gate vacuum line is off from when the MBC was uninstalled?

 

[2ggst1998]

Ya they should be i used the same lines in the same order when the mbc was on. I assume since the problem disappears when one of the vacuum lines is disconnected it may be getting too much boost when its connected?

Noone has ran into this before?

 

[J'sDSM2]

I'm running a similar set up to yours and have a damaged intercooler. It leaks pressure and I have fuel cut due to it.

You should fix your cel's

 

[2ggst1998]

I understand i need to fix them but I'm positive they aren't causing the fuel cut.
And also the car doesn't stumble in 1st it only does it in the other gears. So would this still be a boost leak?

 

[2ggst1998]

Is there suppose to be any boost coming from the BOV vacuum line? Is this a bad BOV? The vacuum line pops off under WOT.

 

[Kapok6]

Boost goes from the intake manifold to the top of the BOV to keep it closed while under boost. The vac line should not be popping off. Is it coming off on the BOV end or the IM end?

 

[d1prospect]

Zip tie your vacuum lines.

 

[Kapok6]

Yeah, I suppose I shouldn't have assumed he/she was actually securing the line with something.