Re: Blow off valve failure? (needsdecaf)
The TCV is NOT connected to the CBV. The CBV is directly connected to the intake manifold and is purely mechanical, responding to vacuum and boost.
The TCV is fed with raw boost from the compressor side of the turbo. It is a solenoid valve with a PWM signal from the ECU. Its controlled output goes to the wastegate actuator (dashpot).
It the TCV sticks open the boost will never go over ~ 4 psi. If it sticks closed (more rare) overboost will occur and a limp mode kicks in will reduced fuel as I recall.
The TCV is NOT connected to the CBV. The CBV is directly connected to the intake manifold and is purely mechanical, responding to vacuum and boost.
The TCV is fed with raw boost from the compressor side of the turbo. It is a solenoid valve with a PWM signal from the ECU. Its controlled output goes to the wastegate actuator (dashpot).
It the TCV sticks open the boost will never go over ~ 4 psi. If it sticks closed (more rare) overboost will occur and a limp mode kicks in will reduced fuel as I recall.
