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Can't build boost after s16g install

Posted by PlanZero, Mar 26, 2016

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  1. PlanZero

    PlanZero Proven Member

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    I just installed a used small 16g, FP race manifold, and 7" FMIC yesterday and now she won't build boost. I did a BLT and couldn't hear anything but the air going through the turbo (I can't even remember if this is normal). When I took her for a drive she stumbled at about 7-8psi. Felt very laggy. I disconnected my MBC and ran fine at about 5psi, but wouldn't go past that. I reconnected the stock MBC and I get the same thing,only going to 5psi. Feels restricted. Is the 16g compatible with a 2g bcs, meant for a T25? Does my MBC need major adjustment after switching turbos?
    The turbo had very little shaft play, I ported the WG hole a little, new gaskets and bolts, SS feed line, reused T25 water lines and drain line (no leaks yet).
    This is my first MHI small 16g and it seems very laggy compared to the old T25. I don't think it's spooling as quickly as it should.
     

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  2. simplejoe

    simplejoe Proven Member

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    See if your wastegate is stuck open
     

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  3. PlanZero

    PlanZero Proven Member

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    I tested the WG when I was doing the BLT. Seems to open and snap shut normally.
    I noticed the flapper was very "wiggly" on the arm it's connected to inside the housing. Is this normal? I'm considering the washer shim mod to see if maybe the flapper isn't sealing shut snugly. Although the WG looked OK maybe it bent slightly in shipping.
     
    Last edited: Mar 26, 2016

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  4. gsxeclipse102

    gsxeclipse102 Proven Member

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    With the wastegate actuator attached you shouldnt be able to wiggle the wastegate flapper arm at all.
     

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  5. PlanZero

    PlanZero Proven Member

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    No I can't. I meant the actual flapper felt loose on it's arm
     

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  6. secretagentstv

    secretagentstv Proven Member

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    For a good BLT you should use water and dishsoap. You could have a wastegate issue or an exhaust leak.
    If your running rich it's probably a boost leak.
    If you drive it around alittle and look for exhaust soot you can find a leak.
    If the wastegate is bent bend it back or get a new one. Or try to shim it. You did exhaust manifold, intake, turbo all at once so it's could be one or all. Good luck though small 16 is a great turbo. Spools close to stock and makes great power.
     
  7. ThunderChild

    ThunderChild Supporting VIP

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    Almost 100% positive youve got a boost leak. You said it stuttered around 7-8 psi, so I'd go leak hunting again.

    You could have other issues like some exhaust leaks exsascerbating the issue, especially a rich condition.

    Go back and triple check it all, BLT the piss out of it, and make sure your shaft play isn't excessive.
     

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  8. Type1DSMr

    Type1DSMr Proven Member

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    What exhaust manifold to turbo gasket are you using? I've had nothing but problems with the extreme psi 6 ply on the fp manifold. I switched to a solid gasket, and it fix my boost problems a while back.
     
    Type1DSMr

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  9. Mauispyder

    Mauispyder Proven Member

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    Stuttering does sound a little more like a boost leak. That being said, my recently installed T28 was super laggy and not building boost, ended up needing the WG tightened up. In my case I have an adjustable WGA but you could shim it. Night and day difference. I believe in Type1dsmer's case, he actually saw the marks from the gasket leak.
     

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  10. PlanZero

    PlanZero Proven Member

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    Interesting. I used a victor reinz mls gasket that I had lying around. I also had a fel pro composite gasket I chose not to use.
    I live on top of a mountain. Tonight I was able to romp on her up the hill and she's now holding steady at 5psi with the stock BCS. This leads me to think wastegate, since leaks tend to manifest themselves as a stumble. Although i dont know why it was stuttering with the mbc (which was working perfectly), but no stutter with WG or BCS pressure. The turbo sounded great and seemed to spool up nicely, albeit at only 5 psi. Felt like a slug going up the mountain. I did notice it seemed to pick up in 4th gear. I'm replacing the half assed wire on the actuator with the proper hitch pin and adding two washers on each WG bolt tomorrow to see if there's a difference. If not I'll try swapping gaskets.
    And I did another BLT to 25 psi. Not a peep. This is actually the first time I've done a BLT in a quiet garage but I'll try soapy water when I have time to pull the bumper.
     

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  11. PlanZero

    PlanZero Proven Member

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    Well I shimmed the actuator then I discovered a coupler that wasn't seating properly so I fixed that. Now it feels like fuel cut at 10psi. I removed the shims, same thing. At 9psi she feels great. At 10psi I start to hear this loud screech from the CAI and a major hiccup, stumble (I know its not fuel cut , just feels that way).
    Triple checked all couplers and t clamps. I did notice that when I run a line directly from the WG actuator to the j pipe I only hit 5psi max, shimmed or not. Is this normal? I thought it should be higher.
     

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  12. Malcalmstunt

    Malcalmstunt Proven Member

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    Make sure your recirculating tube is connected to your blow off valve.
     

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  13. 2gmitsueclipse

    2gmitsueclipse DSM Wiseman

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    The sound you hear is still likely a boost leak as you are describing it. For the blt's you are doing, 25 psi seems like a good enough number to work with. You could even go to 20 for your current setup.
    secretagentstv's suggestion to use soap/water is really helpful for tracking down leaks.

    Here are some additional suggestions:
    • Ensure the car is at operating temp for your testing.
    • Also try testing from an intercooler pipe right after the compressor housing.
    • The dish soap and water should be in a spray bottle. Use liberally on all couplers, fuel injector seals, and around throttle body.
    • Jack the front of the car up (support with jack stands) to gain easy access underneath the car while testing.

    You can also test the wastegate actuator using this method:



    If your setup is using an MBC, you should have it hooked up in this fashion:
    1gvacuumrouteing.JPG

    If you are using the OEM boost solenoid, it should look something like this:

    taboo6cf.png

    Have you tried to re-torque the exhaust manifold, and manifold-to-turbo bolts after a couple heat cycles? Re-torque them only after they have cooled down as you may end up with a dent in the hood if done hot. If an exhaust leak was the issue, I would imagine that it would by easy to spot with the significantly low boost levels you are seeing. I suppose though, it could possibly be a combination of things, so check it anyway to rule it out.
     

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  14. 2gmitsueclipse

    2gmitsueclipse DSM Wiseman

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    While this is a good suggestion for many setups, it does not apply much to the OP's specific issue.
     

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  15. RamenPride

    RamenPride Proven Member

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    J-pipe at the compressor outlet on tight? I've had the two bolts work their way loose before and cause a boost leak that didn't show up on a leak test because it was so big.
     

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  16. Mauispyder

    Mauispyder Proven Member

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    IIRC 7-8psi is usual for WG diaphram springs. You can check by attaching the tube going to the actuator to a bicycle pump (with pressure gauge). One SLOW pump should provide full motion of the actuator arm and with the gauge you can see the pressure it first starts moving and the pressure it's fully open at.
    I'm not sure what CAI screeching sounds like. I don't even know how I'd pinpoint any noise coming from the CAI when I'm running an engine at 10 psi.
    I wouldn't expect fuel cut anyway with a small 16g at 10psi. Are you sure your boost gauge is accurate/not leaking?
    Alternatively I have had a car breakup electrically when under load before. New wires fixed that!
    Good luck!
     

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  17. Malcalmstunt

    Malcalmstunt Proven Member

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    Yes you're correct. But I found myself at 7 psi when I forgot to hook up my recirculating tube
     

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  18. chrysler kid

    chrysler kid Proven Member

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    The op has an automatic dsm, meaning it rarely needs to use a bov


    I would re torque all if your exhaust manifold and turbo bolts. You might have some small exhaust leaks.
     

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  19. PlanZero

    PlanZero Proven Member

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    Thanks for all the responses guys. My cat was running beautifully before this swap, so I'm pretty sure it's related to the turbo, Mani or fmic.

    Retorqued after a few heat cycles. Good to go.
    Boost gauge was accurate before swap. CAI sounds like a screeching owl before she stumbles at 10psi. When I run a line from WG to j pipe, or from BCS, I can't GI above 5psi. No stumble, just won't boost. WG actuator snaps open and shut with a light burst from air hose.
    Had a small leak at j pipe. Fixed it.
    The MBC and bcs were hooked up correctly. The WG actuator appears to be working properly, but I think its an aftermarket piece. It's silver (painted black) and chunkier than every other MHI I've seen. Also it opens and snaps shut quickly.
    What I don't get is the fact that when I'm running off WG pressure or BCS it doesn't go past 5psi. No stuttering. Just maxes out. But when I hook up the MBC I can get up to 9 psi beautifully but once I crank it a little more to 10 she hits a wall.
    Theoretically, I may have a leak above 10psi. Regardless, shouldn't I still be reaching 8-9 on WG pressure and a little more on the BCS?
    I'm very tempted to grab a used MHI actuator just to swap out and eliminate that factor.
    I should also mention that during all my test runs I got two CELs (not consistently, just once). I erased them but one was for MAF high circuit and the other was for WG solenoid or something like that. They didn't come back.
     
    Last edited: Mar 27, 2016

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  20. PlanZero

    PlanZero Proven Member

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    Well Id like to change the name of this thread to "how stupid am I today" because I believe I am truly an idiot.
    Although I rechecked all my t clamps, I was rechecking them with the same impact driver and deep 10mm socket I used to install them.
    This particular eBay kit came with 2.5" pipes and 76mm clamps. Apparently these clamps can be tightened a bit more with a 10mm ratcheting wrench. The kit is great and I love the intercooler (RDT). Mounted just like the ets 7" FMIC, but with no cutting of the bumper. Also, I was able to fit all the pipes without cutting (I already had a GReddy UICP which I connected to). 4 ply silicone couplers. But the clamps could've been smaller. I tightened all 14 clamps another 7-8 turns with a wrench and whoop de doo she pulls like a raped ape. I'm only at 12psi on stock injectors and evo x pump.
    What's odd is the fact that this didn't show up on a BLT, even at 25lbs. I should have been hearing leaks from almost all connections. Now that I think of it, my cheap ass BL tester doesn't have a gauge, and the one time I was able to drag my gf into the garage there was no reading on the boost gauge.:ohdamn::ohdamn::ohdamn:
     

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  21. OGDSM1989

    OGDSM1989 Proven Member

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    Hearing the boost leaks is not always an option, which is why most people use the soap and water method while pumping up the system as this will show each coupler that is leaking ( from what I have found at any psi ). Glad to hear your car is running well and your having fun with it, dont forget your maintenance to keep the car running.
     

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  22. DSMTyson

    DSMTyson Proven Member

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    You do not listen for leaks when doing a boost leak test. This will only allow you to find huge leaks. Use soapy water in a spray bottle like the other 5 million people in this thread said. I say to do another boost leak test, but do it the right way. It's the only way you can be sure that your intake system is sealed.
     

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  23. PlanZero

    PlanZero Proven Member

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    That was my point. Of course I used soapy water. I should have also been hearing leaks if there were so many. The soap only revealed two small leaks.
     

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