Relieve fuel system pressure. See BASIC TESTING article in this section. Remove air valve or dynamic chamber, if necessary. Remove delivery pipe with hoses still connected. Remove fuel injectors. Using wire, secure injectors tightly onto delivery pipe.
CAUTION: Ensure injectors are securely tied to delivery pipe. If not properly secured, fuel may spray from loose connections.
On Protege and 323, connect a jumper wire between terminals F/P and GND in diagnostic connector, located next to battery. See BASIC TESTING article in this section for test connector location. On Miata, install a jumper wire between terminals of Yellow fuel pump check connector. Fuel pump check connector is located on firewall, under windshield wiper motor on Miata.
Turn ignition on for 10 seconds. Turn ignition off and clean injector nozzles. On 4-cylinder models, tilt injectors approximately 60 degrees. On all models, turn ignition on. Check that no fuel leakage exists at injectors. After one minute, a drop of fuel leakage is acceptable. If fuel leakage is excessive, replace faulty injector.

NOTE: Injector delivery volume information is not available for Miata, Protege and 323.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Injector Fuel Leakage