1JZ Single Turbo No Boost After Drift Event - Wastegate Issue

After three laps at a drift event and a 10-minute rest, a 1JZ non-VVTI with a CX Racing GT35 single turbo conversion made zero boost. All vacuum lines, BOV hoses, and intercooler couplers appeared visually intact.

The external wastegate was stuck open or malfunctioning, allowing all exhaust gas to bypass the turbine and preventing the turbo from building boost. Once the wastegate was addressed, boost returned. With the wastegate vacuum hose disconnected (wastegate fully closed), the turbo made 1 bar. With the hose connected, it made 0.5 bar (~7-8 psi), which matched the wastegate's 10 psi spring pressure and confirmed the wastegate was now functioning correctly.

Moderate confidence — Original poster confirmed this resolved the issue