jayrex Posted January 28, 2017 Share Posted January 28, 2017 Very suddenly I'm having low boost issues and I want to test the turbo directly. I can't find the post I'm thinking of, and not sure if I'm remembering the connections correctly. Also any other testing input is appreciated. Whats happening: I usually run 18-19lbs, currently getting 10-12 (spring pressure I'm assuming) What I've done: -Full vacuum leak test, system holds pressure well. -Cleaned out my GrimmSpeed EBCS and tested it by touching to battery and listening for click. Works good. Ohm reading is good too at 32. Cleaned associated vacuum lines. -Took off turbo inlet, no shaft play, blades are perfect, spins smooth. -Its not a tuning issue. WGDC is near 100% and shows on my AP as such. **This is where I need some confirmation and help** - I attached the turbo housing nipple directly to the WG actuator nipple and blocked off the vacuum lines that were removed to install that 'jumper line'. This took my max boost numbers down to 5-6lbs. I was thinking that this test should produce unrestricted boost. Am I wrong and need to connect vacuum from another source? As a next step, all I can think of is to take the downpipe off and eye ball the hot side. Maybe put 20lbs directly into the WG actuator nipple? But before I go through all that work, is there anything else am I overlooking? Link to comment Share on other sites More sharing options...
MilesA Posted January 28, 2017 Share Posted January 28, 2017 If you eliminate the boost controller and connect the wastegate directly to the turbo housing, the wastegate will open sooner that it normally does. The turbo housing is a pressure source, not a vacuum source. As soon as boost pressure from the turbo exceeds the spring pressure on your wastegate, the wastegate will open and your boost will top out. Link to comment Share on other sites More sharing options...
jayrex Posted January 28, 2017 Author Share Posted January 28, 2017 Thanks MilesA. I get all kinds of turned around when it comes to vacuum lines and what is happening at any given time inside them. So it sounds like the test I'm looking for is to just remove the WG actuator line completely (or just pinch it off mid line) and try not to boost to 25lbs. EDIT: Just found this link: http://www.clarks-garage.com/shop-manual/exh-02.htm Explains it pretty simply. Link to comment Share on other sites More sharing options...
jayrex Posted January 28, 2017 Author Share Posted January 28, 2017 Pinched off the wastegate supply line. Still at 10-11lbs. Any ideas where to go next? Wastegate stuck open? Link to comment Share on other sites More sharing options...
CapnJack Posted January 28, 2017 Share Posted January 28, 2017 Sounds like a waste gate issue. Make sure it moves smoothly and that the flapper has not shifted off center. It's been known to shift in the bushing and cause the problem you describe. Link to comment Share on other sites More sharing options...
jayrex Posted January 29, 2017 Author Share Posted January 29, 2017 Sounds like a waste gate issue. Make sure it moves smoothly and that the flapper has not shifted off center. It's been known to shift in the bushing and cause the problem you describe. Makes sense, will update any findings on the dark side. Link to comment Share on other sites More sharing options...
jayrex Posted January 29, 2017 Author Share Posted January 29, 2017 Took off the down pipe and didnt see anything unusual, and tested the actuator with about 15lbs of air. Seemed smooth. But I did find a broken o2 sensor... and havent found the missing piece yet. https://imgur.com/a/bsvT1 Im thinking that piece is stuck in the inlet of the hot side. Its 20deg out and I have a one piece header uppipe setup Link to comment Share on other sites More sharing options...
jayrex Posted January 30, 2017 Author Share Posted January 30, 2017 Problem Solved! Took off the headers, couldn't get any bits to come out, still wasn't sure if anything was in there. So I pulled the whole turbo out... shook it a few times and 'gingle gingle' sound inside. After some more shaking these bits popped out: http://imgur.com/a/e5PzO Almost missed the 2nd smaller cone piece, it didn't come out right away. No damage to the turbo and she's back together and boostin strong! Link to comment Share on other sites More sharing options...
CapnJack Posted January 30, 2017 Share Posted January 30, 2017 Nice job diagnosing!!! Glad you found the issue and everything is working well. Link to comment Share on other sites More sharing options...
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