300ZX V6-2960cc DOHC (VG30DE) (1990)
Camshaft Position Sensor: Customer Interest
Engine - Detonation
Classification:
EM91-005
Section:
ENGINE MECHANICAL
TECHNICAL BULLETIN NTB91-056
Models:
1990 300ZX
Date:
MAY 30, 1991
1990 300ZX CRANK ANGLE SENSOR CAUSING DETONATION
(SPARK KNOCK)
APPLIED MODELS: 1990 300ZX, 300ZX TURBO
APPLIED VIN:
Prior to:
JN1RZ24A-MX050007
(July 3, 1990)
JN1RZ26A-MX050002
(July 3, 1990)
JN1CZ24A-MX050001
(July 4, 1990)
JN1RZ24H-MX500223
(July 20, 1990)
JN1RZ26H-MX500046
(July 3, 1990)
JN1CZ24H-MX500082
(July 4, 1990)
SERVICE INFORMATION:
On some 1990 300ZX vehicles, customers may complain of engine detonation (spark knock). The incident may be caused by the initial ignition timing
being excessively advanced. If the vehicle has this condition, it may be impossible to adjust the timing to the correct initial specification by turning the
crank angle sensor.
The cylinder head assemblies of the incident vehicles may have been improperly machined. This results in the camshaft indexing peg and the crank angle
sensor being off-center. The off-center condition allows excessive force to be applied to the indexing peg which results in damage to the peg. In most
cases, but not all, the indexing peg on the camshaft will be damaged causing the incident of advanced ignition timing.
Crank Angle Sensor
SERVICE PROCEDURE:
Check the crank angle sensor initial ignition timing using a timing light. Note: The CONSULT unit will not give initial timing. If the initial timing is
incorrect, make the necessary adjustments.