Acceleration Enrichment
- In order to test acceleration enrichment function, cold engine operation must be simulated, as acceleration enrichment is not functional above 176°F (80°C). To simulate cold engine, connect a 25-k/ohm resistor wire between coolant sensor wiring connector and vehicle ground.
- Start engine and bring engine speed up to 2500 RPM for short time. Lower chamber pressure should drop as engine speed increases. If lower chamber pressure does not drop, test airflow sensor potentiometer, test control current to differential pressure regulator and test ECU.