49
SURGES/CHUGGLES
Checks Action
DEFINITION: The engine has a power variation under a steady throttle. The engine feels as if it speeds
up and slows down with no change to the throttle.
Preliminary Checks None.
Sensor Checks Check the Heated Exhaust Gas Oxygen Sensor (HEGO) performance.
Fuel System Checks
Check for Rich or Lean symptom that causes the condition.
Run the engine at the speed of the complaint. Monitoring the oxygen sen-
sor will help identify the problem.
Check the fuel pressure while the condition exists. Refer to Fuel System
Diagnosis.
Verify proper fuel control solenoid operation.
Verify that the LPG manual shut-off valve is fully open.
Check the in-line fuel filter for restrictions.
Ignition System
Checks
Check for the proper ignition output voltage using the spark tester J26792 or
the equivalent.
Verify that the spark plugs are the correct type and properly gapped.
Remove the plugs and inspect them for the following conditions:
Wet plugs (oil fouling).
Cracks.
Wear.
Improper gap.
Burned electrodes.
Heavy deposits.
Check the Crankshaft Position (CKP) sensor.
Additional Check
Check the ECM grounds for being clean, tight, and in their proper locations.
Check the alternator output voltage.
Check the vacuum hoses for kinks or leaks.
Check Transmission
To Next Page
Loading...