Lack of Power, Sluggishness, or Sponginess. Chevrolet Metro 2000

For 1990-2009 cars

Checks | Action
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DEFINITION: The engine delivers less than expected power. The speed may increase slightly or may not increase when applying the accelerator pedal.

Preliminary Checks

• | Refer to Powertrain On Board Diagnostic (OBD) System Check .

• | Refer to Symptoms .

• | Compare the customers vehicle with a similar vehicle in order to determine how severe the customers concern is.

• | Remove the air filter element, and check the air filter element for dirt or for restrictions.

• | Check the transmission shift pattern and the down shift operation.

Fuel System Checks

• | Check for a restriction in the fuel supply system. Check for the correct fuel pressure. Refer to Fuel System Diagnosis .

• | Check the fuel injectors. Perform the Fuel Injector Coil Test and the Fuel Injector Balance Test. Refer to Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Between 10-35 Degrees C (50-95 Degrees F) and to Sequential Multiport Fuel Injector Balance Test .

• | Check for contaminated fuel or for poor quality fuel. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .

Ignition System Checks

• | Check for adequate secondary ignition voltage with a J 26792 spark tester or with an equivalent.

• | Check for the correct operation of the ignition control system.

• | Check the reference signal from the CKP sensor with a scan tool. Observe the engine speed parameter while operating the engine at the speed of the concern. The scan tool should indicate steady RPM readings and linear RPM readings while running. If sudden increases or decreases in engine speed are displayed, the engine reference signal is not stable enough for the engine to run correctly. Check for a short to ground in the ignition reference low circuit of the CKP sensor. A short to ground in the ignition reference low circuit of the CKP sensor will cause a faulty engine reference signal to be sent to the PCM.However, this will not set a CKP sensor DTC.

Exhaust System Checks

• | Check the exhaust system for a possible restriction. Refer to Restricted Exhaust System Check .

• | Inspect the exhaust system for damaged pipes or for collapsed pipes. Inspect the muffler for heat damage or for a possible internal failure.

Additional Checks

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Check the PCM grounds for being clean, tight, and in the correct locations. Refer to Engine Controls Schematics

#### Cell 21: Power and Ground

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• | Check the generator output voltage.

Engine Mechanical Check

Check for any of the following engine mechanical conditions:

• | Low compression

• | Incorrect valve timing

• | An incorrect camshaft or a worn camshaft