White Smoke

White smoke indicates unburned fuel during cold engine operation.

The intake manifold heater system is not directly connected to the fuel system but it monitors the temperature of the air to the engine. The thermistor sends varying resistance values to the Electronic Control Module (ECM). The ECM in turn controls the "Wait to Start" light and the heater solenoids.

The intake manifold heater elements operate in both the preheat and postheat modes.

^ In preheat, the ignition switch is on but the engine has not been started.
^ in postheat, the engine is running.

The proper operation of the intake manifold heater system and starting procedures will preclude excessive engine starter motor use and minimize white exhaust smoke when the engine is first started.

NORMAL OPERATION OF THE INTAKE MANIFOLD HEATER SYSTEM

Engine Intake Preheater Post Heater
Manifold Temp. Cycle Time Cycle Occurs
Ign. Key "ON" Ign. Key "ON"
Before Crank After Crank
Cycle Cycle

Above 15°C [59°F] 0-Seconds No

-9°C to 15°C * 10-Seconds Yes
[15°F to 59°F]

-18°C to -9°C 15-Seconds Yes
[0°F to 15°F]

-26°C to 18°C 17-Seconds Yes
[-15°F to 0°F]

Below -26°C [15°F] 20-Seconds Yes

NOTE: The KSB Valve activation voltage is independent of the Intake Manifold Heater Control System. The KSB Valve will be activated any time the intake manifold temperature is above 15°C [59°F], the ignition key is in the ON position and the ECM is monitoring the thermistor (reading resistance).


* Heater Control Modules/Electronic Control Modules with serial numbers below 0080000A will not have a Preheat Cycle during this cycle.