There is another test for the Charge Control Actuator. The start the car and the rod pulls in test is verifying vacuum can get to Chamber A of the CCA. Chamber A is toward the front of the car and Chamber B is toward the rear. Vacuum is applied to Chamber A from 0-4500 rpm. Chamber B is getting Primary boost for all rpm. From 4500 till redline Chamber A is supplied with boost from the second turbo via the Charge Control Solenoid. In the following Image of the back half of the y-pipe, circled is the nipple that supplies second turbo boost through a nipple on the lower intake manifold to the rats nest to the single nipple side of the Charge control solenoid. Highlighted in the vacuum diagram is the path this signal follows. To test the second turbo boost signal is reaching the CCA, tee your boost guage into the Chamber A line and watch for the change from vacuum to boost around 4500 rpm. If the change does not occur trace the lines and check function of the Charge Control Solenoid, lower row second from the front of the car.

 

cymrex, thanks for the tip. Haven't tried that one. Changing that CCA Solenoid will be a PITA, since in the solenoid rack buried under the UIM (sigh)...

 

cymrex, your pic is not attached...

 

Hmm, this site appears to say that the secondary turbo compressor supplies boost to the CCA "Chamber A" without the CCA solenoid? Or maybe they forgot to mention that IMPORTANT bit of info? http://www.autosportracetech.com/RX-...leshooting.htm

 

Just following up on this thread. The 9500-mile old J-spec turbos appear to be fine. The lack of power and subsequent low boost response is due to some other system problem--fuel delivery, exhaust restriction, ignition, oil metering--we've addressed any turbo control related problems.