Spectrum 3.0L GM, Руководство по запчастям и обслуживанию

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LACK OF POWER, SLUGGISHNESS, OR SPONGINESS
Checks Action
DEFINITION: The engine delivers less than expected power. There is little or no increase in speed
when throttling the engine.
Preliminary Checks

Refer to the
Fuel system OBD System Check.

Compare the customer’s engine with a similar unit to verify customer has
an actual problem.
Do not compare the power output of the engine op-
erating on Natural Gas and Propane to one operating on gasoline as the
fuels do have different performance characteristics.

Remove the air fi lter and check for dirt or restriction.

Check the vehicle transmission.

Refer to the OEM transmission diagnostics.
Fuel System Checks

Check for a restricted fuel fi lter, contaminated fuel, or improper fuel pres-
sure. Refer to
LPG Fuel System Diagnosis
.

Check for the proper ignition output voltage with the spark tester
J 26792
or the equivalent.

Check the Regulator and Throttle body for proper installation and lea-
kage. Check all air inlet ducts for condition and proper installation.

Check all air inlet ducts for condition and proper installation.

Check for fuel leaks in supply lines.

Verify that the Fuel Supply Valve on the supply line is open.

Verify that liquid fuel (not vapor) is being delivered to the Regulator.
Sensor Checks

Check the Heated Exhaust Gas Oxygen Sensor (HEGO) for contamina-
tion and performance. Check for proper operation of the TMAP sensor.

Check for proper operation of the TPS and FPP sensors.
Exhaust System Checks
Check the exhaust system for a possible restriction:

Inspect the exhaust system for damaged or collapsed pipes.

Inspect the muffler for signs of heat distress or for possible internal fail-
ure.

Check for possible plugged catalytic converter.
Engine Mechanical
Check
Check the engine for the following:

Engine compression.

Valve timing.

Improper or worn camshaft.

Refer to
Engine Mechanical
in the Service Manual.
Additional Check

Check the ECM grounds for being clean, tight, and in their proper loca-
tions.

Check the alternator output voltage.
If all procedures have been completed and no malfunction has been found,
review and inspect the following items:

Visually and physically, inspect all electrical connections within the sus-
pected circuit and/or systems.

Check the DST data.