Remove throttle body and install a plate, or weld the TB shut. Then drill a small hole into the plate/throttle plate, check its RPM. Go larger and larger with the hole until you reach your RPM point. Then the IAC valve should be able to compensate when there is more load applied to the engine.
2JZ's have an idle up vac control for the power steering, you might be able to adapt something to that using a solenoid on the vac line to control the rise rate.
Just a few ideas.
2JZ's have an idle up vac control for the power steering, you might be able to adapt something to that using a solenoid on the vac line to control the rise rate.
Just a few ideas.