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Discussion Starter · #1 · (Edited)
Got the car pretty much all back together now. Just need to put the hood and grille on. I took it for a drive to see how it felt but now I'm not getting boost :(

Is there a workaround to isolate what's wrong?
 

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Check the wiring to the APC solenoid, tap the knock sensor bolt with a spanner with the ignition on, the APC solenoid should chatter. The impact may have damaged your wiring to the solenoid. Then just check all 3 hoses from the APC solenoid are intact and fitted.

You're not getting more than base boost? Or no boost? I'd check the vacuum line to the boost gauge if you're getting none, because that's very unlikely that the impact completely destroyed boost unless the wastegate arm was bent or broken in the process. Check it's operation and that there is spring resistance by pushing/pulling it gently in its direction of travel
 

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Discussion Starter · #3 ·
Check the wiring to the APC solenoid, tap the knock sensor bolt with a spanner with the ignition on, the APC solenoid should chatter. The impact may have damaged your wiring to the solenoid. Then just check all 3 hoses from the APC solenoid are intact and fitted.

You're not getting more than base boost? Or no boost? I'd check the vacuum line to the boost gauge if you're getting none, because that's very unlikely that the impact completely destroyed boost unless the wastegate arm was bent or broken in the process. Check it's operation and that there is spring resistance by pushing/pulling it gently in its direction of travel
I checked the apc solenoid by seeing if there was flow-through on the R hose with power and none without power. I can hear it click when I turn the key on too.

I'm getting no boost whatsoever. It shows manifold vacuum but not moving the needle into yellow at all...the hose is hooked up to the gauge.

Could the bypass valve be stuck closed?
 

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Discussion Starter · #4 ·
I don't quite get this. It will rev up to 5500 rpm without a hiccup. If I let it fall off rpm from there there is no sputter or stall at all. If I'm understanding the system correctly, this means the bypass valve is working as it should. But there's no boost at all, and when I drove it there was no kick back into the seat like it would if the turbo spooled up.

Not sure where to go here...hoping someone can at least point me in the right direction
 

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I don't quite get this. It will rev up to 5500 rpm without a hiccup. If I let it fall off rpm from there there is no sputter or stall at all. If I'm understanding the system correctly, this means the bypass valve is working as it should. But there's no boost at all, and when I drove it there was no kick back into the seat like it would if the turbo spooled up.

Not sure where to go here...hoping someone can at least point me in the right direction
If you are getting 0 boost and you are 100% sure the boost gauge is connected correctly it's a mechanical fault with the waste gate of the turbo or a leak bleeding off boost.

Have a look under the turbo at the waste gate arm, it may have been damaged. Carefully push pull the arm to feel spring tension in the mechanism to ensure it is working.

Check all your hoses for vacuum leaks, I saw your intercooler connector was kinked pretty badly, ensure that it is fasted properly and hasn't split from the kink (entirely likely) vacuum leaks of this nature can often only open up under boost. Also it's possible your intercooler has a leak in it as it was right near the impact zone. Just have a thorough look around that area... (would have been easier with everything off it.)
 

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Discussion Starter · #6 ·
I checked it (the ic) pretty good before bolting it all back together...I have a spare on the shelf so I would have swapped it right quick if it was suspect. I don't hear any vacuum leaks, but I'd think anything big enough to cause a 0 boost would be big enough to have the car running poorly.

I'm wondering if the wastegate isn't fubar...should the rod move at all because it doesn't move in or out right now.
 

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I checked it (the ic) pretty good before bolting it all back together...I have a spare on the shelf so I would have swapped it right quick if it was suspect. I don't hear any vacuum leaks, but I'd think anything big enough to cause a 0 boost would be big enough to have the car running poorly.

I'm wondering if the wastegate isn't fubar...should the rod move at all because it doesn't move in or out right now.
Vacuum leaks may only become leaks under boost, so they should be called boost leaks. Rubber can seal well against itself in vacuum but when you throw 6-12psi things are going to open up.

The wastegate -
If you're doing it right yes it should move. You can only push it in the plane that it's in of course, you should be able to push it to open the waste gate, if it isn't moving in either direction I'd say it's somehow jammed and probably jammed open to give you no boost ;) . Can you see evidence of damage? Try giving it a wriggle.

Be careful not to damage the diaphragm, don't twist the rod, just be mindful of it when playing around down there.
 

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I don't quite get this. It will rev up to 5500 rpm without a hiccup. If I let it fall off rpm from there there is no sputter or stall at all. If I'm understanding the system correctly, this means the bypass valve is working as it should. But there's no boost at all, and when I drove it there was no kick back into the seat like it would if the turbo spooled up.

Not sure where to go here...hoping someone can at least point me in the right direction
I believe the turbo bypass valve could also have a failed diaphragm, which would allow the boost to bleed off at all times (i.e. failed open). This happened in a previous Saab of mine ('88 9000T), and it caused max boost to be ~20% into the yellow. Upon replacement the car was like night and day ;ol;
 
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