ehos

Ok, back to fixing my 'old man' FD. It makes 10 PSI after 4500 RPM's (very violently boost comes on). I read-re-read the TT troubleshooter and it says

'The Secondary Turbocharger requires the Primary Turbocharger to generate more than 8 psi of boost to properly operate actuators that control the Secondary Turbocharger.'

BUT, my boost gauge reads about 0-3 PSI, maybe 0-5 at times, then when 4500RPM hits, it goes instantly to 10-11 PSI. What could be wrong?

-Checked all hoses for leaks. If it can make take 10 PSI, there should be no boost leaks right? I wish I had everyone else's secondary boost problems. I want 10PSI before 3500 RPM!
-both chambers good
-vac hoses should be good (redid most of them)
-abv is ok, no blow off valve (closed off)
-removed the hoses with pills and it didn't overboost!

Mods - XSPower IC, DP, no ac/ps/airpump. Is my main cat clogged? (It's not getting air, I know that).

What else can I check?

I would ditch it all for seq. system, but it seems like it's already acting like that

Mahjik

iTrader: (1)

Check the Charge Control system.

ehos

"A simple test for the Charge Control Actuator is to start the engine and let it idle, the actuator rod will be pulled in. Stop the engine and remove the hose from Chamber A and the actuator rod will be out."

I did that and it works.

I will check my Turbo Pre-Control door and see if it's 'slightly ajar' as it says. And I might pull my main cat and have a looksee...

DaveW

If you're getting full boost after 4500, it's not a cat problem.

Kento

+1 (well, sort of...)

Check your turbo pre-control actuator, not the CCA. It sounds like the turbo pre-control door is venting practically all the exhaust energy to the secondary turbo (robbing the primary of enough exhaust to spool up-- this system is mostly responsible for regulating boost with the primary turbo), then when the CCV opens up, WHAM! A boatload of boost is released into the intake tract, resulting in the violent transition.

ehos

"Another problem is that the Turbo Pre-Control door is slightly ajar robbing exhaust for the Primary Turbo. The solution is in properly setting the length of Turbo Pre-Control Actuator rod. Disconnect the rod from the the door by removing the C-clip, hold the door closed and set the length of the rod so that one half of the arm pin is hidden by the hole in the rod end. Then reattach the rod, you will have to pull on the rod in order to get the hole to go over the pin of the arm. Remember to put that 5-7mm E-clip back on."

You mean this right? I was going to check that, but I don't really 100% understand how to set the rod. What happens if I set it incorrectly? (Is there a way to set it so it doesn't open? Just as a test?)

Oh yeah, is this like the waste gate control rod on single turbo's, but it instead vents to secondary turbo?

Kento

Look at the "turbocharger overview" drawing on the troubleshooting site carefully. You'll see two actuators next to the primary turbo each actuating a door in the exhaust manifold. One is the wastegate; the other is the turbo pre-control.

The instructions you just quoted state how to set the pre-control rod.

ehos

Blue is precontrol. Red is wastegate. Green is Turbo control.

Finally found a decent pic!