See Figures 1 and 2
Most 180 ZX models sold in the U.S. have an air induction system for the purpose of emission controls. Vehicles sold in California and Canada do not have the air induction system. The system relies on exhaust pulses to siphon fresh air into the exhaust manifold to continue combustion of any unburned mixtures. More details on this system, (which resembles an ordinary air injection system except for the air pump), can be found in Emissions Controls .
Every 24 months or 30,000 miles (38,000 km), the air induction valve filter must be replaced.
- Disconnect the negative cable from the battery.
- Remove the ignition coil to facilitate access to the air induction filter.
- Unscrew the clamps and disconnect the hoses from the valve assembly. Remove the valve assembly, noting its position before removal.
- Remove the four retaining screws and disassemble the air induction valve. Remove the old filter and discard.
- To install, use a new filter and reverse the removal procedures.
Be certain the valve is facing in the correct direction, so that the exhaust gases do not flow backward.