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Discussion Starter · #1 ·
Soooo deep breath, I upgraded my fuel pump , pink injectors, vf30 turbo, and larger top mount. And yes all other supporting mods including and off the shelf cobb map stage 3 that matches my setup..i know I probably need a proper tune but still the car would run half decent..

Anyway now I'm running super lea, 25.00 a/f at idel, NOT WHILE DRIVING. But it still concerning also I was building boost alittle slow but still got up to 14 or 15 lbs pretty quickly. Now I can't even get 10lbs.. idk what's going on, I honestly think an injector isn't firing, or isn't firing enough.. but I feel like I'd get a cal, and my boost is almost my most conceding problem (since I got it used ) maybe it's Burnt out? Idfk , but i feel like I wouldn't even get 10lbs out of it if it was fu#@ed.. any suggestions would be awsome.. I'm think maybe a smoke test to look for leaks on boost, and the running lean at idel thing..idk what to do about that.. I just feel like it's driving as fast as a 92 geo prizum..im sad af. Help me out , any thoughts!?
 

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I would look into post maf intake leaks and boost leaks first as they are the most common. What is the dam?

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Discussion Starter · #3 ·
I have a short log actually ,but idk how to get it on here.. but it's a 16 out of 16. I'm about 90% sure. What's the best way to test for boost leaks, and intake leaks? I could look at YouTube I'm sure. But i thought to test for boost leaks I'd have to take the turbo inlet tube off and pressurized it? What am I looking for in terms of my idel problem? Injectors?
 

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I have a short log actually ,but idk how to get it on here.. but it's a 16 out of 16. I'm about 90% sure. What's the best way to test for boost leaks, and intake leaks? I could look at YouTube I'm sure. But i thought to test for boost leaks I'd have to take the turbo inlet tube off and pressurized it? What am I looking for in terms of my idel problem? Injectors?
I wouldn't drive the car if your afr is lean. Good way to turn a possible simple issue into a new engine senario. What I mentioned will cause idle problems. As will a myriad of other things. start simple and likely then move to the unlikely.

Basically they pressurize the post turbo intake and look for smoke leaking out, it's not that tough. Shops will typically test all of it and compression for under 400 bucks

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Discussion Starter · #5 ·
So an update I figured out the idling problem it was a loose vacuum hose sucking air.. once I put it back on with a hose clamp my idled is fine now the real mystery.... is why I cannot build boost past nine point whatever pounds the drive ability of the car is fine very normal gets up to RPM quickly and as it should but it will not boost past 9 point whatever and I'm starting to think maybe wastegate actuator or boost control solenoid would that even a cause something like this?

Side note I took off my intercooler and pressure-tested it no leaks..
 

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Did you pressure test the rest of the system. The throttle body to intercooler connection is a common leak point, as are the tgvs,

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Discussion Starter · #7 ·
Ok so I really hope someone answers me really super soon lol.. so obviously from the past posts I've been having a huge drop in boost so what I did today was literally just disconnect the vacuum line to my wastegate actuator and I plugged the hose that I disconnected and I tried to drive the car and when I really stepped on it I got up to 22 PSI and shot off like a rocket pretty quick. so what does that mean??? Hahaha. I'm not quite sure what's broken what do I need to replace what caused me from not even being able to reach 6 pounds of boost and when I disconnect that vacuum line I'm able to hit 22 lb n super overboost.. please help me. What do i need to replace and or fix?!
 

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Discussion Starter · #9 ·
I specifically bought products that matched a cobb stage 3 map.. with a pro tune my vehicle would be more aggressive yes, but it would still run decent
 

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If you upgraded the injectors wouldn't you need a proper tune?
^^^ this ^^^

I specifically bought products that matched a cobb stage 3 map.. with a pro tune my vehicle would be more aggressive yes, but it would still run decent
if you definitely cannot get a protune right now, i would at the very least:

1. go over all my connections again. what TM did you put on, and did you replace the throttle body hose with a better one than the OEM? theres no pressure while at idle, so perhaps when you put it under load, a less than tight or improperly fitted connection can create loss of pressure. i personally know just from going to stage 2, the OEM TB hose gave way. as did some gaskets in the BPV.

2. shell out 100-200 bucks to do a [pro] etune. some of these etuners are the best in the business, and can assist you with this issue. the cobb maps, tho specific to the mods you made, are complete crap. cant stress this enough. no shade towards cobb, because they do what they do, but the OTS maps are just band aids so your car doesnt blow up. and by the looks of this particular map, it will blow up if you push it.

hope you get it sorted out.
 

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Discussion Starter · #12 ·
I agree about the tune, I didn't know about etune.. I'll have to look into it. But the boost pressure,.. I've found that when I disconnect the vacuum line from wastegate actuator I get full boost ( over boost) no problem , no more than normal lag. But i have still yet to hear what that means.. barley 7psi with vacuum line to wastegate actuator, over 20 psi without..so what's broken. Bcs? Wastegate actuator? It's not the tune, because about a day before I lost my boost I was building 15 16 psi no problem.
 

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At this point I would rule out the waste gate actuator, turbo, probably boost leaks as well.. it IS able to build boost, it's just that the boost control system isn't functioning correctly. I would inspect all of the lines associated with boost control as well as the EBCS. If you put the car into test mode and turn the key on you should be able to hear the EBCS cycling on and off. Since it was working better than it is now I would assume the lines are were hooked up correctly, but it still should have been hitting over 15psi.

What year model car do you have, and exactly what map are you running (link?). I haven't looked through all of their maps in quite some time, but I don't recall ever seeing a map for the vf30. They have a stage 3 map for bugeyes that's designed for a vf39 and STI TMIC.. specifically which intercooler are you running? Many of the cheap larger intercoolers don't work as well as stock.
 

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Discussion Starter · #14 ·
Yeah I agree I don't believe I have a large boost leak at least enough to cause such a significant change in pressure . the wastegate actuator seems to be holding as much pressure as a turbo can throw at it, when its not hooked up to the vacuum line. so I was leaning towards boost control solenoid or something associated with boost control as well, I just don't know enough about it or what to look for.. I took the boost control solenoid off of the car ,hooked it up to the terminals of a 12-volt battery and sprayed it out with cleaner that I saw on another Forum cycled through a lot of times but still to no avail, can't get past 7psi.. I have a 02 bugeye, and I actually swapped back to the stock tmic yesterday. I'll post that link to where you can look at the Cobb Maps but I honestly don't think my Boost problem is associated with the tuning of the map because then I would have never been able to even build 15 psi previously if it was a tune issue..https://www.cobbtuning.com/maps/2002-2003-subaru-impreza-wrx-stage-3-vf30-turbo-map
 

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Let’s begin by describing what a turbo wastegate is. A wastegate is essentially a device that bypasses some exhaust flow around the turbine section of a turbocharger to control maximum boost. A wastegate is usually controlled by a pressure actuator that is connected to manifold pressure. The wastegate is normally closed, held shut by a spring inside the actuator canister. When preset pressure limits are exceeded, the actuator progressively opens the wastegate, allowing exhaust flow to bypass the turbine, thus regulating manifold boost pressure. On the surface, it sounds like a simple premise, and in fact, a wastegate is a simple device. The problem comes from the pressure in the exhaust system, called turbine inlet pressure that can bear against the valve, overpowering the spring in the actuator, and forcing the wastegate open at lower than intended boost levels.

Original equipment turbocharger wastegate actuators are selected or engineered for a specified boost level and turbine inlet pressure. To keep costs down, such actuators are usually just big enough to do the job at the stock boost levels. If the turbocharger boost is increased for additional airflow and performance, the stock wastegate actuator is frequently incapable of holding the wastegate fully closed until the higher boost level is reached. This happens because turbine inlet pressure also increases as boost pressure rises. The fix is to use a bigger spring in the wastegate actuator to hold it closed until the desired peak boost is achieved, however, that also requires a bigger actuator diaphragm to override the heavier spring when the desired boost level is reached. That’s why Banks created the Big Head actuator that’s used on many of its diesel power systems.

The net affect is that the turbocharger comes up to peak boost more quickly and then maintains that boost level throughout the engine’s RPM range for optimum mid-range torque and top end performance. It’s another example of the engineering expertise you get from Gale Banks Engineering. We do it right.
 

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If the turbocharger boost is increased for additional airflow and performance, the stock wastegate actuator is frequently incapable of holding the wastegate fully closed until the higher boost level is reached. This happens because turbine inlet pressure also increases as boost pressure rises. The fix is to use a bigger spring in the wastegate actuator to hold it closed until the desired peak boost is achieved, however, that also requires a bigger actuator diaphragm to override the heavier spring when the desired boost level is reached.

While true, this statement doesn't apply to the situation at hand. The WGDC has already been tuned in the Cobb map to hit a peak 16.5psi (+/-0.7psi). No modification of the wastegate is needed since it is well within the stock wastegate/actuator's ability to hit and hold the boost targets in the map. Also considering the fact that it had no problems hitting 22psi at 100% WGDC it's pretty clear that the wastegate/turbo is not the problem here.


If the ECU isn't pulling boost, and the turbo has no problem building boost when at 100% WGDC, that points to there being a mechanical issue with the boost control system. I would guess something is wrong between the nipple on the compressor outlet and the wastegate actuator. It is behaving as if the compressor outlet is plumbed directly to the actuator without the EBCS bleeding any air off between the two.




It wouldn't hurt to see a data log of what's happening.. you can upload it to Google Docs and set it as "public" so we can see it.
 

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Discussion Starter · #19 ·
PROBLEM FIXED!!!! i think hahaha

so this is what i did, i checked out lines coming from turbo and wastegate, noticed the pill was on wastgate side of the "T" so i shortened it and put in on the other side near turbo nipple. took off the ebcs again, hooked it up to a 9v batt and made sure i could blow through it. because you're no supposed to be able to blow through it apparently when its off the car or disconnected.. anyway it all honestly i dont think that those things had anything at all to do with the problem getting fixed.. what actually (in my opinion) fixed the problem was that i uninstalled the new cobb map, installed my old map (off the shelf stage 2) then reinstalled the new stage 3 cobb map.. and i was able to build boost, way better than before.. i have a link here of a data log after i fixed the problem. which god only knows what problems lay wait to be found in that data log hahahahaha

https://docs.google.com/spreadsheets/d/1UpKsnZLokKbXTtTz7Ef8w_SQ5Kpfxji9BbHrzzRUD2I/pubhtml

but more importantly than anything is thank you guys so much for trying to help me or even responding. it means allot to us little guys trying to make our way. again many many thanks..
 
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