#5570, "RE: 420a Idle is at 4000 RPM need help!" In response to In response to 2
heres how I check for leaks in the intake. Just cap the TB with your hand, the motor should die instantly, if it doesnt or tries to still run you have a vac leak somewhere. If it does shut off then I would start looking to the IAC since the air must be bypassing the throttle plate.