Random boost levels, negative LTFT, and tons of vibes

Anthony Amador

Anthony Amador

Replacing this and that..
Greenie N00B Member
So i just recently got my MS3 up and running pretty good. I was seeing close to 0 LTFT, and was making about 19PSI at WOT with the Cobb Stage 3 OTS tune.

On Monday i had my first hiccup, my LTFT shot to -20.88 and are stuck there no matter what throttle position (other than WOT). The engine is no longer making good boost, its actually random, for example, If i accelerate in 4th gear it will hit 8PSI (PSI IS RANDOM AT TIMES, BUT NEVER REACHES FULL BOOST) and stay there, but if i let off the gas and accelerate again it'll climb up to 17 TO 19 PSI and accelerate normally.

The engine feels like it has no power 80% of the time, and the vibrations are insane. I'm used to a lot of vibrations since i'm running all 3 Damond Motorsport mounts, but this is just insane. Any ideas what could cause this?

Someone said i should put my EBCS in "interrupt" mode, but i cannot find a place on the stock turbo to run it to, so i only have it going to the wastegate, and the intake. The third opening is capped off. So is the OEM turbo capable of running the EBCS like this?

CODES ON CAR
- P2178 - RICH AT IDLE
- P2188 - RICH OFF IDLE
- P2004 - VTCS STUCK OPEN
- P0403 - EGR CODE

NEW PARTS
- OEM MAF
- OEM MAP
- 1 STEP COLDER PLUGS

MODS
- COBB CAI
- AP V3
- CS EBCS
- CS INJECTOR SEALS
- CS HPFP INTERNALS
- CX RACING FMIC KIT (I HAVE THE JBR FMIC PIPING ORDER BUT THEYRE RUNNING BEHIND)
- STOP TECH BBK
- ISC COILOVERS
- VTCS DELETE (JUST THE BUTTERFLIES IN THE INTAKE)
- DAMOND EGR DELETE FULL KIT
 
Okay, so I did a boost leak test, and the system will hold pressure. I replaced the BOV gasket that mates it to the FMIC piping as it was leaking. I did the soapy water method, I no leaks anywhere. I checked my EBCS again, and replaced the vacuum lines with new silicone hose. I ran it the OEM way that the 2 port was ran. (Bleed setup)

My average boost is about 1-5psi MAX!

then out of nowhere I’ll do a normal pull and I have regular boost 18psi+. This is so confusing, I’ve even gone back and cleaned my MAF sensor.
Is it possible a leak from the exhaust side would cause this?

I will be posting some logs later tonight once I get my computer to work.

Fuel trims still pegged at -20.88.

HELP PLEASE!
 
Sounds like your primary O2 sensor if your fuel trims never move. LTFT will zero out when you go into open loop (WOT). What do your STFTs look like? Those are the numbers that'll be actively adjusting based on throttle.

It's also possible that you're having an issue with your EBCS or IWG not functioning properly and bleeding air out of the system preemptively which is why you're running rich/having boost issues.
 
To eliminate any wastegate or mechanical turbo issue just connect the wastegate to a boost source instead of the EBCs. You should get consistent pressure every time. It's one way to make sure the WG is functioning nornally.

Are you running a factory exhaust system and catalytic converter? Overly rich fuel trims will degrade the catalyst quickly and can cause it to be partially blocked. The engine cant breathe properly thus leading to excessive fuel trims and improper boost levels.

Think of it being partially clogged and depending on the moment the chuck is restricting some flow which is why you are seeing random psi levels
 
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broda said:
Sounds like your primary O2 sensor if your fuel trims never move. LTFT will zero out when you go into open loop (WOT). What do your STFTs look like? Those are the numbers that'll be actively adjusting based on throttle.

It's also possible that you're having an issue with your EBCS or IWG not functioning properly and bleeding air out of the system preemptively which is why you're running rich/having boost issues.
Click to expand...

Well i just replaced the O2 sensors (again) with OEM parts. I thought it might have been a bad replacement at first. The EBCS is brand new 3 port from corksport. I did notice that it was installed wrong! Lines were reversed, line that went to WG was on the intake tube, and vice versa. i rerouted them correctly, and no change.

L337TurboZ said:
To eliminate any wastegate or mechanical turbo issue just connect the wastegate to a boost source instead of the EBCs. You should get consistent pressure every time. It's one way to make sure the WG is functioning nornally.

Are you running a factory exhaust system and catalytic converter? Overly rich fuel trims will degrade the catalyst quickly and can cause it to be partially blocked. The engine cant breathe properly thus leading to excessive fuel trims and improper boost levels.

Think of it being partially clogged and depending on the moment the chuck is restricting some flow which is why you are seeing random psi levels
Click to expand...

I do have an aftermarket DP, but its a cheapo. How would i go about connecting it to a boost source? Route the WG to the intake pipe?
I would love to try this out so i can rule out the EBCS.
 
broda said:
Run a line from a boost source (ie. the vacuum line from intake manifold to BPV/BOV) directly to the wastegate
Click to expand...

Thank you for the help!! I will try that today. Do i just leave the BOV without the vacuum line on or do i use a T fitting?

I'm learning all of this step by step, so i appreciate the patience guys haha.
 
Anthony Amador said:
Thank you for the help!! I will try that today. Do i just leave the BOV without the vacuum line on or do i use a T fitting?

I'm learning all of this step by step, so i appreciate the patience guys haha.
Click to expand...
Edit: I'm dumb
 
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how many lines are you using on the EBCS? If only two then just connect the one going into the EBCS to the outlet one of the EBCS.

If it is a 3 port do the same, it wont matter if it "bleeds to atmosphere" because youre only doing this as a test to see if the wastegate it capable of opening at its predetermined spring pressure
 
L337TurboZ said:
how many lines are you using on the EBCS? If only two then just connect the one going into the EBCS to the outlet one of the EBCS.

If it is a 3 port do the same, it wont matter if it "bleeds to atmosphere" because youre only doing this as a test to see if the wastegate it capable of opening at its predetermined spring pressure
Click to expand...

I am only using 2 ports on the EBCS. One from the wastegate to the EBCS, and another from the intake to the EBCS.

I just switch them to check spring pressure?
 
you dont switch them. connect them together. go to your auto parts store and get a set of Vacuum Tee fittings. just find one that is straight and not a T. take the two hoses at the EBCS and connect them together using the straight fitting. Your EBCS will not be controlling the wastegate and the wastegate should open around 12psi.
 
Yup, do that ^ Sorry, I had a brain fart since I'm so used to EWG setups that I forgot that there's already a boost source from the turbo going into the IWG.
 
Okay,

What do i do if i still have no boost after doing this? bad waste gate? The wastegate duty seems okay at WOT its about 50-70%

If i did have to replace the wastegate what do you guys recommend?
 
You're running off spring pressure so you'll be seeing less than your commanded in the tune. WGDC won't come into play with your EBCS bypassed. We're basically looking for consistency in your achieved boost pressure to make sure that the IWG is working properly. If your boost is still all over the place running off spring pressure then the EBCS should be okay and that's when you'll looking be into the IWG.
 
wastegates themselves rarely fail. unless the rod broke, theres a crack at the flap inside the turbocharger then its probably ok. What we are trying to do now is to see if the turbo and the wastegate can hit a consistent boost level without aid of the ECU. This is why you are bypassing the EBCS. Ignore you WGDC. Can you post a pic of how you have the vacuum lines connected bypassing the EBCS so we are sure you have it connected right

the next step would be to remove the downpipe, remove the wastegate rod from the flap, and then manually open the flap so you can inspect for cracks. Any air that bypasses the turbine wheel will cause a loss of boost pressure. The turbine cant spin up to speed consistently. You wouldn't notice an exhaust leak because it would be internal to the exhaust system.

While you have the DP off, check for shaft play in the turbo and make sure it isnt spewing oil and things like that out the backside of the turbo.
 
Okay guys, so this is where i'm at right now. I did the above mentioned jump on my wastegate.

I jumped the wastegate to my turbo inlet tube, and i'm still getting random boost numbers.

1st - 1-5PSI
2nd - 1-5PSI
3rd - SOMETIMES i can reach 14-16PSI
4th - 5-8PSI
5th - 1-5PSI
6th - 1-3PSI

Another thing to note is that my turbo does not sound normal, one second it'll sound perfectly healthy and ill make 18PSI, but when i'm ot making boost it sounds like a ton of air is coming out of my exhaust, like someone is blowing air out of the turbo without spooling it. It's weird.

Today i plan on removing the downpipe and see what i can find, to be fair my wastegate looks rusty! I feel like it's not closing all the way, i have about 25% of the normal power i would usually get.
 
It'll sound that way because you're essentially venting all of your boost pressure directly into your exhaust if the IWG is opening at low pressure.

You shouldn't be getting 16 PSI on spring pressure so it'll be good to check out the IWG and actuator. One thing to check (if you haven't yet) before pulling everything off is that your vacuum line going from the turbo to the actuator/IWG isn't becoming kinked or collapsing which could also create the weird issues you're having.
 
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broda said:
It'll sound that way because you're essentially venting all of your boost pressure directly into your exhaust if the IWG is opening at low pressure.

You shouldn't be getting 16 PSI on spring pressure so it'll be good to check out the IWG and actuator. One thing to check (if you haven't yet) before pulling everything off is that your vacuum line going from the turbo to the actuator/IWG isn't becoming kinked or collapsing which could also create the weird issues you're having.
Click to expand...

I actually replaced all the vacuum lines with silicone lines, including the one going from the turbo to the bottom of the wastegate. Worst comes to worst and my actuator is bad, would an OEM replacement be sufficient? Is there any aftermarket options? I saw a forge Motorsports one, but it has mixed reviews.

I''l update you guys later tonight! Thanks so much, hopefully i can get this working.
 
I have a spare OE IWG. If you wanted to wait a week or two. I went EWG and still have my old one on the turbo but I can buy a IWG delete bracket and send you my old one.

Just pay for shipping and PM me your address. I'll order the bracket now and send you the WG once I install it.
 
L337TurboZ said:
I have a spare OE IWG. If you wanted to wait a week or two. I went EWG and still have my old one on the turbo but I can buy a IWG delete bracket and send you my old one.

Just pay for shipping and PM me your address. I'll order the bracket now and send you the WG once I install it.
Click to expand...

I will check out my wastegate tonight!

I really appreciate that, honestly. Thanks so much i'll PM you once i check it out.
 
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