Lack of Power/Sluggish/Spongy

SYMPTOM DESCRIPTION:

Engine delivers less than expected power. Little or no increase in speed when accelerator is pushed down part way.




SYSTEM OR COMPONENT TO CHECK ACTION

COMPUTER INPUTS/OUTPUTS CHECK: - CONTROL UNIT
Grounds for being clean, tight,
and in their proper location.




FUEL CHECK: - FUEL PRESSURE:

- CONTAMINATED FUEL

- RESTRICTED FUEL FILTER




IGNITION CHECK: - IGNITION COIL OUTPUT VOLTAGE
Check for spark using appropriate spark tester.
- SPARK CONTROL operation.
- IGNITION TIMING.





EMISSIONS CHECK: - EGR SYSTEM:
Valve or Solenoid operation.






EXHAUST CHECK: - RESTRICTION.
1. With engine at normal operating temperature,
connect a vacuum gauge to any convenient
vacuum port on intake manifold.
2. Run engine at 1000 rpm and record
vacuum reading.
3. Increase rpm slowly to 2500 rpm.
Record vacuum reading at 2500 rpm.
4. If vacuum at 2500 rpm decreases more than
3" Hg, from reading at 1000 rpm, the exhaust
system should be inspected for restrictions.
5. Disconnect exhaust pipe from engine and repeat
Step 3 & 4. If vacuum still drops more than
3" Hg, with exhaust disconnected, check for
exhaust manifold restriction and valve timing.





ENGINE/TRANSMISSION CHECK: - ALTERNATOR OUTPUT VOLTAGE.
Replace or Repair, if less
than 9 volts or greater than 16 volts.
- A/C operation.
- ENGINE COMPRESSION.
- ENGINE VALVE TIMING.
- ENGINE CAMSHAFT
Check for wear and proper application.
- TORQUE CONVERTER CLUTCH (TCC) operation.
- TRANSMISSION SHIFT POINTS.