12HT turbo woes (1 Viewer)

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Jul 28, 2016
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Originally put this in the 70s tech but feel like that was the wrong place, so moving it here.

Recently gave the old 12HT a bit of an overhaul, new injector pump and new turbo. Was running sweet at 10psi at ~350c for a few weeks, then about a week ago something happened and the boost now doesn't want to get over 7psi. EGT is waaay up on the slightest inclines too (like 550 - 600 going up a highway ramp at 90). At the same I've noticed that we've suddenly lost 200rpm also, used to hold 2000 at 90kmh now does 2200 to 2300. I have no idea if all these are connected, I'll tackle them one at a time I suppose.

I've checked all the vacuum lines and all turbo hoses for leaks and nada. I did notice the rebuilders reused my old waste gate actuator, could it possibly have given up from looking ugly next to the new shiny stuff? Tried disconnecting the waste gate altogether and went for a rather controlled drive. Didn't push it hard, but felt like didnt want to push much above 10psi. Exhaust blockage maybe? I'm running out of ideas.

Edit - darn can't delete the other post.
 
My first port of call would be the people that did the work . Exhaust blockage is a long shot. How about a terribly clogged air filter?
 

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