Testing TCA
 

I am currently trying to diagnose low secondary boost. Could someone please confirm whether the pressure side of the TCA should hold pressure when applied with a hand pump.

Currently when I pump up the pressure side I cant get any more than 5 PSI of pressure into the valve. This then bleeds off almost as fast as I can put it in.

Cheers Tim.

It should hold about 15psi without any leaking. The vacuum side should hold about 30"Hg. Don't apply any more than that.

Dave

Cheers for that Dave.

I figure that having ruled nearly everything else out the 4 or so PSI im losing when the secondary turbo comes on could well be being lost out of the pressure side of the TCA. A possibility??

Well if it's being lost out the pressure side it's leaking into the vacuum side. So yes, I would expect to see the boost tail off as the flow needs of the turbos increase with RPM, and the TCA slowly closes off that exhaust supply.

Gotta find a used actuator though - Mazda asks something unholy like $400 for that actuator.

Dave