Lack of Power/Sluggish/Spongy/Stumble

Engine delivers less than expected power. Little or no increase in speed on slight acceleration.

POSSIBLE CAUSE ACTION


Hot air tube not connected Check inlet air temperature system (TAC)
to air cleaner - air damper in "Testing Procedures" in Emissions
door binding or not opening



EGR malfunction Check EGR system in "Testing
Procedures" in Emissions



Spark timing - excessive retard Check Spark Controls (EST, ESC) in
"Fuel Injection and Computerized Engine Controls"



Defective EFE valve Check Early Fuel Evaporation system
in "Testing Procedures" in Emissions



Initial timing incorrect Check Ignition Timing in "Adjustment
Procedures" in Emissions



Restricted exhaust Check Catalytic Converter in
"Testing Procedures" in Emissions



Poor or contaminated fuel Recommend higher grade fuel