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    #1

    Not holding boost

    I've been tinkering with it for a couple days and can't figure out what it is. After 5000ish rpms boost dies off to around 12 psi. in first and second it dies off around 4000 rpms. but up to that it will fluctuate from 14-16 in 4th and 5th. These aren't exact as they vary each time earlier it held 16 psi without fluctuating to 5500 rpms. I didn't push it past that as I don't like runing it that hard

    It did this before when only 3 bolts were holding the turbo on when I first got it. The bolts are tight with stage 8 locking nuts so I know that's not the issue. I have an eBay bov but it was holding 18 psi to redline with it, but I switched back to the bpv setup to be sure and still have the same issue. Vaccume at idle was 19 now ranges from 14-18, if it idles steady it still ranges from 16-19. I can't find any vaccume leaks at all, the waste gate still has a firmness to it when opening it by hand. I'm at a loss, the only thing I have left to test is the boost controller but I doubt its that
    Tags: None
    #2
    Make a fitting that repalces your air filter and lets you pressurise the intake tract. You have a leak, you just haven't found it yet. This is assuming you don't have an afm anymore... since if you do and there's any leak downstream of it, the car won't hardly run at all and you have a whole nuther problem.
    '90 AWD Protege, full GTR drivetrain swap, ~320 whp daily driver, RIP, and
    '90 AWD Protege, yet another GTR swap, Open class rallycar with a Toyota GT4 gearbox swap, thus crossing the line between hobby and mental illness. And a Brabus E55 K8, removing all doubt.
    http://www.wihandyman.com/forum/vbpi...?do=view&g=110
    http://www.cardomain.com/ride/2599486

    Comment

      #3
      I still have the stock afm, the only other upgrades are vj11 and probe smic. So there's very few places it can leak between turbo and throttle body, all the piping is tight and not ripped. I've traced every vaccume line I can find.

      I have a 3 day weekend from work so anything you guys can think of ill try. I'm going to swap out a boost controller tonight if its not raining

      Comment

        #4
        I had someone else look at it, he said there's no leaks and it runs fine other than the boost tapering off.

        He told me the turbo is out of its efficiency or its starting to go bad? I'm guessing he meant seize up? There's very little shaft play in it as of Saturday anyway.

        Comment

          #5
          And now its not making any power at all till 4000 rpms. It's like at 4k it gets 100 hp boost. But boost still builds normally.


          I'm confused at this point

          Comment

            #6
            take the 20 min and make a boost leak tester .. you cant check for leaks without pressurizing the system


            Comment

              #7
              make sure the waste gates closing too
              92 protege lx-

              94 protege lx-

              95 escort gt-ms2e/ms2extra pre3.3alpha5 gslender v2.8-e85-vj23@12lbs----dead--

              are you a thinker, or a believer?

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                #8
                If you still run an afm then you do not ha e a coldside boost leak. If the turbo is failing then it prettymuch has to be laying a huge smoke trail. That leaves wg stuck or exhaust plug. . It is real easy to verify wg function and it sounds like that has been checked. so check your cat. Dead cat makes lotsa backpressure...
                '90 AWD Protege, full GTR drivetrain swap, ~320 whp daily driver, RIP, and
                '90 AWD Protege, yet another GTR swap, Open class rallycar with a Toyota GT4 gearbox swap, thus crossing the line between hobby and mental illness. And a Brabus E55 K8, removing all doubt.
                http://www.wihandyman.com/forum/vbpi...?do=view&g=110
                http://www.cardomain.com/ride/2599486

                Comment

                  #9
                  I found the leak. When I replaced the manifold the gasket for between the turbo and manifold were in 3 pieces and nobody could get one in for a week. So I got one of those metal sheets ( not the liquid stuff in a tube) for exhaust gaskets and made one, aparently it couldn't hold up to the heat. I can't hear the leak but I can feel it pushing air out at idle. I just orderd a felpro set

                  Then today the cel came on, codes for bpv, afm, o2 sensor, and ignition coil. all of the are fixed now except the coil and I'm shopping for it now. Guess that's why it was runing like **** last night, its runing semi decently now other than it misses on warm start ups for about 30 seconds, after that it doesn't miss at all

                  The waste gate did close all the way when I had it all apart

                  Comment

                    #10
                    Well now there's yer problem.
                    '90 AWD Protege, full GTR drivetrain swap, ~320 whp daily driver, RIP, and
                    '90 AWD Protege, yet another GTR swap, Open class rallycar with a Toyota GT4 gearbox swap, thus crossing the line between hobby and mental illness. And a Brabus E55 K8, removing all doubt.
                    http://www.wihandyman.com/forum/vbpi...?do=view&g=110
                    http://www.cardomain.com/ride/2599486

                    Comment

                      #11
                      Yep, I'll be pulling it apart next weekend again. Is there a particular coil I should get? I've read mixed results about msd ones.

                      Comment

                        #12
                        Just replaced the gasket and now its worse?

                        I'm getting a 16-19 psi spike before it comes down to 14 then goes down to 10. It is not leaking at all

                        Comment

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