Hesitation, Sag, Stumble. Chevrolet Beretta 1996

For 1990-2009 cars

#### Hesitation, Sag, Stumble

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
Definition: Momentary lack of response as the accelerator is pushed down. Can occur at all vehicle speeds. Usually most severe when first trying to make the vehicle move, as from a stop sign. May cause engine to stall if severe enough.
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | Go to Step 2 | Go to Powertrain On Board Diagnostic (OBD) System Check

2

1. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found, correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom?

--

Go to Step 16

Go to Step 3

3 | Perform the careful visual/physical checks as described at the start of Symptoms section. Is the action complete? | -- | Go to Step 4 | --

4

1. Check the TP sensor for binding or sticking. Voltage should increase at a steady rate as the throttle is moved toward wide open Throttle.
2. Repair the TP sensor if there is a malfunction found.

Was a problem found?

--

Go to Step 16

Go to Step 5

5

1. Check the MAP sensor for proper operation. Refer to Manifold Absolute Pressure Sensor Output Diagnosis .
2. Repair if there is a malfunction found.

Was a problem found?

--

Go to Step 16

Go to Step 6

6

1. Check for fouled spark plugs.
2. Replace the spark plugs if there is a malfunction found.

Was a problem found?

--

Go to Step 16

Go to Step 7

7

1. Check the Ignition Control Module for proper grounds.
2. Repair if there is a malfunction found with the grounds.

Was problem found?

--

Go to Step 16

Go to Step 8

8

1. Check for poor fuel pressure. Refer to Fuel System Diagnosis
2. If a problem is found, repair as necessary.

Was a problem found?

--

Go to Step 16

Go to Step 9

9

1. Check for contaminated fuel.
2. If a problem is found, repair as necessary.

Was a problem found?

--

Go to Step 16

Go to Step 10

10

1. Perform the Fuel Injector Solenoid Coil Test and Fuel Injector Balance Test
2. If a problem is found, repair as necessary.

Was a problem found?

--

Go to Step 16

Go to Step 11

11

1. Check for proper FEB system performance. Use Table Evaporative Emission Control System Diagnosis
2. If a problem is found, repair as necessary.

Was a problem found?

--

Go to Step 16

Go to Step 12

12

1. Check for proper function of the thermostat. Also check for proper heat range.
2. If a problem is found, repair as necessary.

Was a problem found?

--

Go to Step 16

Go to Step 13

13

1. Check the generator for proper output voltage. The generator output voltage should be between the specified values.
2. If a problem is found, repair as necessary.

Was a problem found?

11V-16 V

Go to Step 16

Go to Step 14

14

1. Check the intake valves for valve deposits.
2. If deposits are found, remove as necessary.

Were deposits found on the intake valves?

--

Go to Step 16

Go to Step 15

15

1. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no malfunctions have been found, review/inspect the following items:

• | Visual/physical inspection.

• | Scan tool data.

• | All electrical connections within a suspected circuit and/or system.

3. If a problem is found, repair as necessary.

Was a problem found?

--

Go to Step 16

Check for Service Bulletins

16 | Operate vehicle within the conditions under which the original symptom was noted. Does the system now operate properly? | -- | System OK | Go to Step 2