After Start Enrichment
- Connect test harness between differential pressure regulator and vehicle harness. Connect multimeter to test harness. Disconnect wiring from coolant temperature sensor and leave open. Ground high tension lead (terminal 4) from ignition distributor.
- Crank starter for 3 seconds. Let key return to on position. Differential pressure regulator current reading should increase to more than 120 mA for 20-50 seconds, then return to 80-110 mA range.
- If not, check starter signal to terminal 24 of ECU connector. Check signal from relay board to starter motor (terminal 15a on starter). On 5-cylinder models, check between ECU terminals 2 and 21. See VOLTAGE CHECKS and RESISTANCE CHECKS charts for appropriate testing procedure. If all wiring is good, replace ECU.