I've had a heck of a time diagnosing this problem.

When I apply WOT, i will hit 0psi, and then it will slowly rise to around 5psi. When I hit 4500 rpm, the secondary turbos cause my boost to rise to about 10psi, but it is extremely shaky, bounces back and forth between 8 and 10 psi. I'm assuming this is a leak, but I'm not sure where to check.

I have silicon couplers for all of my large diameter pipes, and I have screw hose clamps on all but the ABV (BOV). The BOV fittings seem tight with the stock hose clamps.

I do believe I hear air leaking when I engage the secondary turbos, but obviously I have no idea where to look if this is indeed a leak...

Any ideas of where I should check first without ripping apart this engine.

Oh, and I replaced all of my vacuum hoses with silicon hoses around 7 years ago. They 'seem' to be holding up just fine, so I don't think I need to remove my manifold and look at the rats nest...

 

One more thing...

I have/am going though the boost test from autosportracetech.com.

The second step says to remove the double throttle actuator vacuum line and that there should be no vacuum present? When I remove this, my vacuum on my boost gauge does not change at all.

 

pull the hose. feel if the hose is pulling vacuum.

no boost gauge needed

precontrol/wastegate solenoids may be done. bad precontrol could be dumping exhaust into the second turbo before the primary is pumping 10psi. wastegate solenoid could be having trouble during duty control.

check the wire colors to make sure the right plugs are on the right solenoids.

they all have the same B/W wire, but check the other one.

Y/L is turbo control vacuum. bolted to acv behind the precontrol/wastegate solenoids

L/Y is Precontrol

L/W is Wastegate (also has a white dot on the connector and solenoid)

 

rented a mityvac...my ABV only holds 4psi of pressure...so I need a new BOV. If this is the only problem I will be smiling after I replace it.

 

ugh nevermind, the abv and crv hold 15psi when I apply pressure to their top ports...still searching for the problem.

 

Ok found the problem with the primary turbo...the actuator rod came off. Now my secondary turbo sounds soundssounds like i have a boost leak. Solid boost until 4500 rpm then falls to 5psi and sounds like air is leaking. Hopefully ill have it all worked out tomorrow.

 

i recently had this problem. the turbo control solenoid had gone bad. lucky for me it only acted up when it was hot so i could diagnose it easily.

i tapped in to the hose that goes from rats nest to the pipes behind the air pump with a tee fitting. then hooked it up to my boost gauge and went for a drive.

when cold- the gauge read 0psi. when i got to 4500, the gauge switched to vacuum.

when hot (problem temp)- the gauge read 0psi. at 4500, it didnt switch to vacuum like it was supposed to.

i also jacked up the car and verified that the actuator worked with both vacuum and pressure separately.

 

So when you hit 4500rpm, your boost dropped to almost 0psi? I'm struggling to fix this. I boost great with the primary, but when the secondary is supposed to go on, it drops down to between 0 and 5psi. I also hear a high pitched sound when I let off the gas above 4500, and a POP out of my exhaust (probably from unburned fuel because the turbos are not providing enough air).

 

I completed this test from http://www.autosportracetech.com/RX-...g.htm#Pressure

"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, see also Boost Test Step 5."

When my car shuts off, the rod pushes out immediately before I can remove the hose from chamber A.

Does this help diagnose my issue?

 

i hooked my boost gauge up to the output hose from the turbo control solenoid!
this will let you test drive and determine whether the solenoid is working properly.
When you do this, you will not read actual boost pressure in the manifold because the hose is not going to the manifold.

no because the CCA solenoid is switched off when the key is off. just pull the hose off and listen for air rushing in/out. should hear a psssh.
this is testing the Vacuum System for leaks. Not the CCA.
CLICK ON BOOST STEP 5 and see its not testing the CCA.

since the CCA is actuating, it is probably not the issue. you can KOKO test it and see it move each time. that is the test for CCA

 

 

although it may seem like a CCA issue because the pressure drops off after the switch, it is not.

the CCA relies on the pressure produced by the secondary turbo. if the turbo control actuator does not turn on the secondary turbo all the way, then there is not enough pressure to equal the primary boost and the CCA will not work.

start with the turbo control solenoid/actuator by doing that test i show above

 

I will try this this weekend and hopefully it helps

 

Ok, tried several things to no avail.

I replaced the turbo control solenoid, the second turbo control solenoid, and the charge control solenoid.

When I switch over to my secondary, or go WOT above 4500 rpm, I get 2psi, and when I let off the gas I hear a 1 second sound that sounds like someone rolling their R in spanish for 1 second. or perhaps the turbo winding down.

Does this mean my secondary turbo is shot, or that the turbo actuator is not opening? Any ideas?

 

Sounds like the compressor wheel is hitting the housing imo.

I had a similar issue, low boost and whirring noise.

 

Excellent...so looks like I may be rebuilding my turbos!

Oh well, they've lasted me 70k miles and 30k from the previous owner.

 

Pop off the intake piping and check for play.

If there is substantial amounts that is the problem for sure.

 

Did you solve the problem? Was your secondary turbo toast? If the nut came loose you will have plenty of aluminum in the intercooler and have to replace it.

I have the same problem that you describe. Gonna check my turbo control actuator and solenoid.