Nissan Repair: Pulsar CJ11 engine not performing, mass air flow sensor, air fuel mixture


Question
hie Von- I have a Nissan Pulsar CJ11 that is giving me problems. The engine is cutting off whilst on idle. A few weeks back, this only happened when I braked to halt and leave the car to idle on its own. now, the car is suddenly loosing power on the drive and without my foot on the accelerator, the idle becomes rough and in most cases, the engine goes off.one observation i have made is that if pull off the switch to the mass air flow sensor and then start the engine, it runs a bit fine, only to become rough and eventually cut off when i connect back the switch whislt the engine is running.

Answer
Aldren,

First, you need to check the codes to see if the computer is picking up a defective idle air control valve or a bad air meter.

Mode I - Exhaust Oxygen Sensor Monitor

Use Mode I to determine if the Oxygen Sensor is functioning properly.

Warm the engine to normal temperature.

Run the engine above 2000 RPM under no load while looking at the ECU.

Make sure the GREEN LED goes on and off more than five times during ten seconds at 2000 RPM.

If the number of flashes are not more than five, replace the oxygen sensor. If the LED does not flash, check the sensor's circuit.

Mode II - Mixture Ratio Control Monitor

Use Mode II to determine if the air/fuel mixture is cycling correctly.

Warm the engine to normal operating temperature.

Turn the dial on the ECU fully clockwise (or if you have a switch, turn it on).

After the LED flashes twice, turn the dial fully counter clockwise (or turn the switch off).

Run the engine above 2000 RPM under no load while looking at the ECU.

If the RED LED blinks simultaneously with the GREEN LED, the air/fuel mixture is cycling properly.

If the RED LED stays off, the mixture is more than 5% rich.

If the RED LED stays on, the mixture is more than 5% lean.

If the RED LED stays on or off above 2000 RPM, complete the diagnostics before beginning repairs.

Mode III - Stored Fault Code Reporting

Use Mode III to retrive all stored trouble codes in memory.

Turn the ignition switch on, but do not start the engine.

On the ECU, turn the diagnostic mode selector screw fully clockwise (or if you have a switch, turn it on). Wait until the LED flashes 3 quick bursts, then turn the screw fully counter clockwise (or turn the switch off).

The check engine light will begin to flash trouble codes. Red flashes are units of ten and green flashes are units of one. (red-3 flashes, green-1 flash = code 31) Note all codes until it begins to loop.

To clear all stored codes, turn the screw fully clockwise (or turn the switch on). Wait until the LED flashes 4 quick bursts, then turn the screw fully counter clockwise (or turn the switch off). To retain the codes in memory, simply turn the ignition off.

KA24E Codes:

11 Crankshaft Position Sensor Circuit

12 Mass Air Flow Sensor Circuit

13 Engine Coolant Temperature Sensor Circuit

14 Vehicle Speed Sensor Circuit

21 Ignition Signal Missing in Primary Coil

31 Engine Control Unit (ECU)

33 Oxygen Sensor Circuit

41 Air Temperature Sensor Circuit

43 Throttle Position Sensor Circuit

55 No Malfunctions

Complete list of Codes for other models:

11 Crank Angle Sensor/Camshaft Position Sensor

12 Air Flow Meter/Mass Air Flow Sensor

13 Engine Coolant Temperature Sensor

14 Vehicle Speed Sensor

21 Ignition Signal

22 Fuel Pump

23 Idle Switch

24 Throttle Valve Switch

25 Idle Speed Control Valve

28 Cooling Fan Circuit

31 ECU

32 EGR Function

33 Heated Oxygen Sensor

34 Knock Sensor

35 Exhaust Gas Temperature Sensor

36 EGR Control-Back Pressure Transducer

37 Knock Sensor

38 Right hand bank Closed Loop (B2)

41 Intake Air Temperature Sensor

42 Fuel Temperature Sensor

43 Throttle Position Sensor

45 Injector Leak

47 Crankshaft Position Sensor

51 Injector Circuit

53 Oxygen Sensor

54 A/T Control

55 No Malfunction

63 No. 6 Cylinder Misfire

64 No. 5 Cylinder Misfire

65 No. 4 Cylinder Misfire

66 No. 3 Cylinder Misfire

67 No. 2 Cylinder Misfire

68 No. 1 Cylinder Misfire

71 Random Misfire

72 TWC Function right hand bank

73 TWC Function right hand bank

76 Fuel Injection System Function right hand bank

77 Rear Heated Oxygen Sensor Circuit

82 Crankshaft Position Sensor

84 A/T Diagnosis Communication Line

85 VTC Solenoid Valve Circuit

86 Fuel Injection System Function right hand bank

87 Canister Control Solenoid Valve Circuit

91 Front Heated Oxygen Sensor Heater Circuit right hand bank

94 TCC Solenoid Valve

95 Crankshaft Position Sensor

98 Engine Coolant Temperature Sensor

101 Front Heated Oxygen Sensor Heater Circuit right hand bank

103 Park/Neutral Position Switch Circuit

105 EGR and EGR Canister Control Solenoid Valve Circuit

108 Canister Purge Control Valve Circuit

Check or replace the sensor(s) and related components corresponding the list of stores trouble codes.

Mode IV - Switch Operation Monitor

Use Mode IV to determine if the Throttle Position Sensor (TPS), Starter circuit and/or Vehicle Speed Sensor (VSS) are in proper working order.

Turn the ignition switch on, but do not start the engine.

Turn the dial on the ECU fully clockwise. After the LED flashes 4 times, turn the dial fully counter clockwise.

Make sure the RED LED is turned off.

Make sure the RED LED turns on when depressing the gas pedal. If not, check or replace the Throttle Position Sensor.

Make sure the RED LED turns on when turning the ignition key the START position. If not, check or replace the starter.

Drive the vehicle with the ECU unbolted and within view. Make sure the GREEN LED turns on when speed is 12 MPH or more. If not, check or replace the Vehicle Speed Sensor.

Mode V - Real Time Diagnostic Function

Use Mode V to determine if the Crankshaft Position Sensor (CPS), Mass Air Flow (MAF) sensor and/or Ignition signal are working properly.

Start engine.

Turn the dial on the ECU fully clockwise.

After the LED flashes 5 times, turn the dial fully counter clockwise.

Make sure LEDs do not flash for 5 minutes when racing or idling the engine.

If it flashes, count the number of flashes, turn engine off, and see the following 3 paragraphs.
Perform real-time diagnosis insepction and repair or replace malfunctioning part if present.

If LEDs do not flash for 5 minutes, turn engine off.

If the RED LED flashes 3 times for 1.5 seconds, check the Crankshaft Position Sensor. Check the harness continuity at CPS when the engine is stopped. Inspect the harness for dust and clean if necessary. Check the pin terminal at ECU for bends and remove them as necessary. Reconnect harness and recheck continuity. During real-time diagnosis, tap the harness connector or component and check if trouble code is displayed. If so, replace terminal.

If the GREEN LED flashes twice-3 times for 0.5 seconds, check Mass Air Flow Sensor. Check the harness continuity at MAF when the engine is stopped. Inspect the harness for dust and clean if necessary. Check the pin terminal at ECU for bends and remove them as necessary. Reconnect harness and recheck continuity. During real-time diagnosis, tap the harness connector or component and check if trouble code is displayed. If so, replace terminal.

If the GREEN LED flashes 4 times for 0.2 seconds 3 times, check the ignition signal. Check the harness continuity when the engine is stopped. Inspect the harness for dust and clean if necessary. Check the pin terminal at ECU for bends and remove them as necessary. Reconnect harness and recheck continuity. During real-time diagnosis, tap the harness connector or component and check if trouble code is displayed. If so, replace terminal.

Now, after you determine that all is corrected make sure you have good plugs, wires, cap, rotor and fuel filter.