Ok, it boosts. It boosts and boosts and boosts. This non seq isn't too bad. I don't fell the kick as hard as the seq, but it's smooth.

Anyhow, the car has boost. I could live with the lag, but it keeps on boosting. How do you tone it down? Wait, that's a whole different can of worms.

So where do I go from here. I don't think I have a leak. It's got to be in the whole seq setup.

Things I've checked:
Vac Chamber
Pressure Chamber
Check Valves - They are all new. All pointing in the right direction.
CRV - Good
Blow off Valve - Good
Turbo Control Solenoid - New
Charge relief Solenoid - Replaced, used but good.
Vac hose job - rechecked connections. I almost have a mental picture imprinted in my head!
Gutted the Cat - it wasn't that dirty.
Tried the non-seq, it boosts fine.

Thanks again technonovice.

One more thing, If I wanted to keep it non seq, can I just keep it the way it is?

 

You never said what you specific numbers were like in non-sequential. What was the boost?

What means did you use to test the pressure and vacuum chambers? That field check where you pull the lines off to listen to the psst is inconclusive.I'd test them with a Mity Vac pump or the like.

On the Turbo Control Actuator (TCA), there are 2 forces required to operate it properly: pressure and Vacuum. You can see 2 lines in the vacuum diagram. There is one under the hood of the car if you do not have one printed or downloaded. You replaced ONE solenoid, but what about the other. Which one DID you replace?

I'd return the car to sequential because YOU CAN fix it. Let me study the diagram a minute to see how we can proceed.

 

Get the car back to SEQUENTIAL and do this test that will monitor the secondary turbo.
At the Charge Relief there is a small vacuum hose behind the 1" hose that bends 90-degrees. Tee a test gauge on the small line behind that 1" hose.

You should see no activity until 3500 rpms where it should roll up to roughly 8 psi by 4500 rpms. Over 4500 rpms it should read 10 psi.

If this checks out then we can move on to TCS. If not then maybe there is a wastegate problem. I need to review the diagram more to go from here, but this should give you time to tee the above test.

 

Of course I have the exact same problem... (5psi on secondary boost)
I read wher one of you suggested testing the arm.. Can I just pull the Actuator Arm on the secondary turbo control or should I avoid pulling on the rod while the car is not running?

 

Pulling on it by hand won't reveal much. You need to see it will move by testing both the vacuum and pressure sides of the actuator by putting a pressure & vacuum hand pump on the top of the appropriate metal lines that head down to the actuator. No leaks & both sides move the actuator.

 

Was your boost healthy BEFORE the hose job?

 

I did use the mity Vac to test the champers. Both held pressure at 14psi. In non seq, my boost is 10 psi at 3500, and creeps to like 12 or 13 near redline. Feels real strong and pulls like a *****!

The solenoids I replaced are 'J' on the diagram and the other one is the one on top of the ACV labled 'Solenoid Valve, Turbo Control'. This is the solenoid that went bad when the temp got hot. It has known to cure the same exact problem on one of the member's car.

The car was doing 8-7-8 before the vacuum hose job. That leads me to believe that I might have screwed the connections up somewhere, but I'm telling you, I checked that thing over and over and over, well you get the pic.

I won't quit. I will keep diagnosing the problem I hope to find this problem because I've seen countless number of people with the same exact same problem. There's got to be a common denominator. I'll report back after my findings.

Thanks.

 

i am having that same problem. i have had it for almost a year now. when i reach 4000 to 4500 rpm at full throttle my car starts to sound really loud and n/a. sounds like it wants to blow up. had perfect boost when i first got the car. then lost boost completely and tried to redo the lines on my own and got no boost until i reached higher rpms and it pulled all the way to redline. now that i had the vacuum lines professionally done, i get really strong boost in the lower rpms but after 4500 rpms boost drops and i cant shift about that rpm without losing boost when i get back on the gas.let me know if you find anythng out. thanx

 

Hey! I swaped out my Turbo Control (solenoid located under the UIM) with my friends... and tested. my DEFI boost gauge is stuck on Backorder so I went with the 'butt dyno' second gear I couldnt really feel or hear the changeover (as usual).. BUT in 3rd gear I could feel it and feel more than the 5psi boost on the secondary (defintely 10psi). I put my intake on and I can hear the turbos spool better. Again, I can hear everything actually working in 3rd gear (I punch it from 30mph, till redline) but not from a dead stop.. Why is that? Why does it work from a roll in 3rd... perhaps the vacuum chamber is suspect too.

 

How hard was that to do? I need to replace my turbo control solenoids under the extension manifold (UIM). Did you need to remove the extension manifold? When removing the extension manifold, does the elbow and throttle body come off too? Any special tools? A procedure outline would be helpful. Thanks in advance!

 

Here's the part number for the pair of turbo control solenoids that go under the UIM--valve, duty solenoid N3A1-20-285

1-way check valves part numbers:

green/white, HE41-13-995 (vacuum line and double throttle control lines)
green/black, N930-13-995A (pressure chamber and vacuum chamber lines)

 

Correction! N3A1-20-285 solenoid pair are the wastegate and precontrol solenoids.

The vacuum side turbo control solenoid part number is N3A1-18-741. This is the solenoid that apparently fails quite frequently.

I'm not sure what the pressure side turbo control solenoid part number is...

 

Probably so. I've replaced damned near everything except for the charge control actuator and vacuum chamber.

 

FWIW, my problem was a vacuum chamber completely filled with OIL! Replaced the chambers (both pressure and vacuum) with a new chambers, and the second turbo comes online properly now. I also replaced the PCV valve with a new one to prevent the vacuum chamber from filling up again. A bad PCV will pressurize the oil pan (when under boost pressure), causing an oil mess @ the filler neck, and forcing more oil through the primary turbo, thus oiling the entire intake tract. The oil will work its way through the vacuum lines, and will ultimately fill up the new vacuum chamber again.