LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Suzuki >> 2006 >> Verona Luxury >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Introduction >> Diagnostic Information and Procedures >> Lack of Power, Sluggishness or Sponginess
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Lack of Power, Sluggishness or Sponginess

DEFINITION: 

The engine delivers less than expected power. There is little or no increase in speed when the accelerator pedal is partially applied. 

LACK OF POWER, SLUGGISHNESS OR SPONGINESS - DIAGNOSIS PROCEDURE

Step Action Value (s) Yes No
1 Were the Important Preliminary Checks performed? - Go to Step 2. Go to Symptom Diagnosis .
2
  1. Verify the customer's complaint.
  2. Compare the performance of the customer's vehicle with a similar unit.

Does the problem exist?		 - Go to Step 3. System OK
3
  1. Inspect the air filter for excessive contamination.
  2. Replace the air filter as needed.
  3. Check the transaxle shift pattern and down shift operation.

Does the transaxle operate properly?		 - Go to Step 4. Go to Step 5.
4 Check the fuel system pressure.
Is the fuel system pressure within specifications?		 310 kPa (45 psi) Go to Step 7. Go to Step 6.
5 Repair the transaxle as needed.
Is the repair complete?		 - System OK -
6 Repair the fuel system as needed.
Is the repair complete?		 - System OK -
7 Check for a restricted fuel filter or contaminated fuel.
Is the problem found?		 - Go to Step 8. Go to Step 9.
8 Repair or replace any components as needed.
Is the repair complete?		 - System OK -
9
  1. Check the ignition system output for all of the cylinders using a spark tester.
  2. Check for proper ignition control operation.

Is the ignition system operating properly?		 - Go to Step 10. Go to Step 11.
10
  1. With the engine at normal operating temperature, connect a vacuum gauge to a vacuum port on the intake manifold.
  2. Operate the engine at 1,000 rpm.
  3. Record the vacuum reading.
  4. Increase the engine speed to 2,500 rpm.
  5. Note the vacuum reading at a steady 2,500 rpm.

Does the vacuum decrease more than the value specified?		 10 kPa (3 in. Hg) Go to Step 12. Go to Step 15.
11 Repair or replace any ignition system components as needed.
Is the repair complete?		 - System OK -
12 Inspect the exhaust system for restrictions and damaged or collapsed pipes.
Is the problem found?		 - Go to Step 13. Go to Step 14.
13 Repair or replace any components as needed.
Is the repair complete?		 - System OK -
14
  1. Check the cylinder compression and valve timing.
  2. Inspect the camshaft for excessive wear.

Is the problem found?		 - Go to Step 15. Go to Step 16.
15 Repair or replace any engine components as needed.
Is the repair complete?		 - System OK -
16
  1. Check the Engine Control Module (ECM) grounds for being clean, tight, and in their proper location.
  2. Check the exhaust recirculation valve for being open or partially open all the time.
  3. Check the torque converter clutch operation.
  4. Check the A/C system operation.
  5. Check the generator output.
  6. Repair the generator if the output is not within the specified range.

Are all checks and repairs complete?		 12 - 16 V System OK -
scientia non olet · About LEMON Manuals