Engine Controls - Intermittent Engine Surge/Hesitation

Classification:
EC87-012

Reference:
TS87-135

Date:
August 24, 1987

INTERMITTENT ENGINE HESITATION/SURGING

APPLIED VEHICLE(S):
1986.5-1987 Truck, 1987 Pathfinder, 1987 Van, 1987 Sentra Coupe and 4WD Wagon, 1987 Pulsar NX (XE)

SERVICE INFORMATION





Some of the Applied Models built prior to the VINs shown may exhibit intermittent engine hesitation or surging under load. The condition "feels" as if the ignition is shut off for less than a second and then turned back on.

SERVICE PROCEDURE

For vehicles that exhibit this symptom, check the engine systems using the driveability diagnostic procedure in the EF & EC section of the appropriate Nissan Service Manual. This will include a complete self-diagnosis procedure at the vehicle ECU and a complete follow up with trouble-shooting on any trouble codes, until a code 44 or all clear code is achieved.

NOTE:
If a code 11 (crank angle sensor) occurs in a vehicle with manual transmission, clear the memory and repeat the self-diagnosis check. In some vehicles, the code 11 will appear in the self-diagnosis memory any time the ignition switch is turned to the "Start" position while the clutch pedal is not fully depressed.

If the intermittent condition persists after all engine systems are in proper working order according to the tests above, then perform the following test procedure.

Test Procedure

1. Depress and release the accelerator pedal several times prior to performing steps.





2. Connect an ohmmeter at the throttle sensor connector with the positive + side to pin 'd' (terminal side with connector disconnected) and the negative - side to the throttle sensor base plate as shown.

3. Resistance should be oo. Move the positive side to pins 'd' and 'f'. Resistance should remain at 00.

4. If the resistance is anything other than 00, repeat steps 2 and 3.

5. If the resistance is still anything other than 00, replace the throttle sensor with the appropriate part listed below. If the throttle sensor is replaced, be sure to adjust it using the procedures in the appropriate Service Manual.

NOTES:
E16i engines: the idle speed must be set with the throttle sensor disconnected before adjusting the throttle switch as described in the Service Manual under Throttle Valve Switch Adjustment.

VG30i engines: for slight off-idle hesitation on Truck/Pathfinder models, set the initial timing at exactly 14°.





PARTS INFORMATION

The improved throttle sensor has been installed on production vehicles beginning with the VINs.